diff --git a/esphome/analyze_memory/cli.py b/esphome/analyze_memory/cli.py
index 718f42330d..44ade221f8 100644
--- a/esphome/analyze_memory/cli.py
+++ b/esphome/analyze_memory/cli.py
@@ -15,6 +15,11 @@ from . import (
 class MemoryAnalyzerCLI(MemoryAnalyzer):
     """Memory analyzer with CLI-specific report generation."""
 
+    # Symbol size threshold for detailed analysis
+    SYMBOL_SIZE_THRESHOLD: int = (
+        100  # Show symbols larger than this in detailed analysis
+    )
+
     # Column width constants
     COL_COMPONENT: int = 29
     COL_FLASH_TEXT: int = 14
@@ -191,14 +196,21 @@ class MemoryAnalyzerCLI(MemoryAnalyzer):
                     f"{len(symbols):>{self.COL_CORE_COUNT}} | {percentage:>{self.COL_CORE_PERCENT - 1}.1f}%"
                 )
 
-            # Top 15 largest core symbols
+            # All core symbols above threshold
             lines.append("")
-            lines.append(f"Top 15 Largest {_COMPONENT_CORE} Symbols:")
             sorted_core_symbols = sorted(
                 self._esphome_core_symbols, key=lambda x: x[2], reverse=True
             )
+            large_core_symbols = [
+                (symbol, demangled, size)
+                for symbol, demangled, size in sorted_core_symbols
+                if size > self.SYMBOL_SIZE_THRESHOLD
+            ]
 
-            for i, (symbol, demangled, size) in enumerate(sorted_core_symbols[:15]):
+            lines.append(
+                f"{_COMPONENT_CORE} Symbols > {self.SYMBOL_SIZE_THRESHOLD} B ({len(large_core_symbols)} symbols):"
+            )
+            for i, (symbol, demangled, size) in enumerate(large_core_symbols):
                 lines.append(f"{i + 1}. {demangled} ({size:,} B)")
 
             lines.append("=" * self.TABLE_WIDTH)
@@ -268,13 +280,15 @@ class MemoryAnalyzerCLI(MemoryAnalyzer):
                 lines.append(f"Total size: {comp_mem.flash_total:,} B")
                 lines.append("")
 
-                # Show all symbols > 100 bytes for better visibility
+                # Show all symbols above threshold for better visibility
                 large_symbols = [
-                    (sym, dem, size) for sym, dem, size in sorted_symbols if size > 100
+                    (sym, dem, size)
+                    for sym, dem, size in sorted_symbols
+                    if size > self.SYMBOL_SIZE_THRESHOLD
                 ]
 
                 lines.append(
-                    f"{comp_name} Symbols > 100 B ({len(large_symbols)} symbols):"
+                    f"{comp_name} Symbols > {self.SYMBOL_SIZE_THRESHOLD} B ({len(large_symbols)} symbols):"
                 )
                 for i, (symbol, demangled, size) in enumerate(large_symbols):
                     lines.append(f"{i + 1}. {demangled} ({size:,} B)")
diff --git a/esphome/components/cover/automation.h b/esphome/components/cover/automation.h
index 752e0398c1..c0345a7cc6 100644
--- a/esphome/components/cover/automation.h
+++ b/esphome/components/cover/automation.h
@@ -4,8 +4,7 @@
 #include "esphome/core/automation.h"
 #include "cover.h"
 
-namespace esphome {
-namespace cover {
+namespace esphome::cover {
 
 template<typename... Ts> class OpenAction : public Action<Ts...> {
  public:
@@ -131,5 +130,4 @@ class CoverClosedTrigger : public Trigger<> {
   }
 };
 
-}  // namespace cover
-}  // namespace esphome
+}  // namespace esphome::cover
diff --git a/esphome/components/cover/cover.cpp b/esphome/components/cover/cover.cpp
index 3062dba28a..8f735982f1 100644
--- a/esphome/components/cover/cover.cpp
+++ b/esphome/components/cover/cover.cpp
@@ -6,8 +6,7 @@
 
 #include "esphome/core/log.h"
 
-namespace esphome {
-namespace cover {
+namespace esphome::cover {
 
 static const char *const TAG = "cover";
 
@@ -212,5 +211,4 @@ void CoverRestoreState::apply(Cover *cover) {
   cover->publish_state();
 }
 
-}  // namespace cover
-}  // namespace esphome
+}  // namespace esphome::cover
diff --git a/esphome/components/cover/cover.h b/esphome/components/cover/cover.h
index d5db6cfb4f..6c69c05e71 100644
--- a/esphome/components/cover/cover.h
+++ b/esphome/components/cover/cover.h
@@ -7,8 +7,7 @@
 
 #include "cover_traits.h"
 
-namespace esphome {
-namespace cover {
+namespace esphome::cover {
 
 const extern float COVER_OPEN;
 const extern float COVER_CLOSED;
@@ -157,5 +156,4 @@ class Cover : public EntityBase, public EntityBase_DeviceClass {
   ESPPreferenceObject rtc_;
 };
 
-}  // namespace cover
-}  // namespace esphome
+}  // namespace esphome::cover
diff --git a/esphome/components/cover/cover_traits.h b/esphome/components/cover/cover_traits.h
index 79001c3b03..723516318b 100644
--- a/esphome/components/cover/cover_traits.h
+++ b/esphome/components/cover/cover_traits.h
@@ -1,7 +1,6 @@
 #pragma once
 
-namespace esphome {
-namespace cover {
+namespace esphome::cover {
 
 class CoverTraits {
  public:
@@ -26,5 +25,4 @@ class CoverTraits {
   bool supports_stop_{false};
 };
 
-}  // namespace cover
-}  // namespace esphome
+}  // namespace esphome::cover
diff --git a/esphome/components/font/__init__.py b/esphome/components/font/__init__.py
index 32e803f405..2667dbdbdf 100644
--- a/esphome/components/font/__init__.py
+++ b/esphome/components/font/__init__.py
@@ -486,6 +486,8 @@ class GlyphInfo:
 
 
 def glyph_to_glyphinfo(glyph, font, size, bpp):
+    # Convert to 32 bit unicode codepoint
+    glyph = ord(glyph)
     scale = 256 // (1 << bpp)
     if not font.is_scalable:
         sizes = [pt_to_px(x.size) for x in font.available_sizes]
diff --git a/esphome/components/font/font.cpp b/esphome/components/font/font.cpp
index add403fe98..5e3bf1dd20 100644
--- a/esphome/components/font/font.cpp
+++ b/esphome/components/font/font.cpp
@@ -6,42 +6,147 @@
 
 namespace esphome {
 namespace font {
-
 static const char *const TAG = "font";
 
-// Compare the char at the string position with this char.
-// Return true if this char is less than or equal the other.
-bool Glyph::compare_to(const uint8_t *str) const {
-  // 1 -> this->char_
-  // 2 -> str
-  for (uint32_t i = 0;; i++) {
-    if (this->a_char[i] == '\0')
-      return true;
-    if (str[i] == '\0')
-      return false;
-    if (this->a_char[i] > str[i])
-      return false;
-    if (this->a_char[i] < str[i])
-      return true;
+#ifdef USE_LVGL_FONT
+const uint8_t *Font::get_glyph_bitmap(const lv_font_t *font, uint32_t unicode_letter) {
+  auto *fe = (Font *) font->dsc;
+  const auto *gd = fe->get_glyph_data_(unicode_letter);
+  if (gd == nullptr) {
+    return nullptr;
   }
-  // this should not happen
-  return false;
+  return gd->data;
 }
-int Glyph::match_length(const uint8_t *str) const {
-  for (uint32_t i = 0;; i++) {
-    if (this->a_char[i] == '\0')
-      return i;
-    if (str[i] != this->a_char[i])
+
+bool Font::get_glyph_dsc_cb(const lv_font_t *font, lv_font_glyph_dsc_t *dsc, uint32_t unicode_letter, uint32_t next) {
+  auto *fe = (Font *) font->dsc;
+  const auto *gd = fe->get_glyph_data_(unicode_letter);
+  if (gd == nullptr) {
+    return false;
+  }
+  dsc->adv_w = gd->advance;
+  dsc->ofs_x = gd->offset_x;
+  dsc->ofs_y = fe->height_ - gd->height - gd->offset_y - fe->lv_font_.base_line;
+  dsc->box_w = gd->width;
+  dsc->box_h = gd->height;
+  dsc->is_placeholder = 0;
+  dsc->bpp = fe->get_bpp();
+  return true;
+}
+
+const Glyph *Font::get_glyph_data_(uint32_t unicode_letter) {
+  if (unicode_letter == this->last_letter_ && this->last_letter_ != 0)
+    return this->last_data_;
+  auto *glyph = this->find_glyph(unicode_letter);
+  if (glyph == nullptr) {
+    return nullptr;
+  }
+  this->last_data_ = glyph;
+  this->last_letter_ = unicode_letter;
+  return glyph;
+}
+#endif
+
+/**
+ *  Attempt to extract a 32 bit Unicode codepoint from a UTF-8 string.
+ *  If successful, return the codepoint and set the length to the number of bytes read.
+ *  If the end of the string has been reached and a valid codepoint has not been found, return 0 and set the length to
+ * 0.
+ *
+ * @param utf8_str The input string
+ * @param length Pointer to length storage
+ * @return The extracted code point
+ */
+static uint32_t extract_unicode_codepoint(const char *utf8_str, size_t *length) {
+  // Safely cast to uint8_t* for correct bitwise operations on bytes
+  const uint8_t *current = reinterpret_cast<const uint8_t *>(utf8_str);
+  uint32_t code_point = 0;
+  uint8_t c1 = *current++;
+
+  // check for end of string
+  if (c1 == 0) {
+    *length = 0;
+    return 0;
+  }
+
+  // --- 1-Byte Sequence: 0xxxxxxx (ASCII) ---
+  if (c1 < 0x80) {
+    // Valid ASCII byte.
+    code_point = c1;
+    // Optimization: No need to check for continuation bytes.
+  }
+  // --- 2-Byte Sequence: 110xxxxx 10xxxxxx ---
+  else if ((c1 & 0xE0) == 0xC0) {
+    uint8_t c2 = *current++;
+
+    // Error Check 1: Check if c2 is a valid continuation byte (10xxxxxx)
+    if ((c2 & 0xC0) != 0x80) {
+      *length = 0;
       return 0;
+    }
+
+    code_point = (c1 & 0x1F) << 6;
+    code_point |= (c2 & 0x3F);
+
+    // Error Check 2: Overlong check (2-byte must be > 0x7F)
+    if (code_point <= 0x7F) {
+      *length = 0;
+      return 0;
+    }
   }
-  // this should not happen
-  return 0;
-}
-void Glyph::scan_area(int *x1, int *y1, int *width, int *height) const {
-  *x1 = this->offset_x;
-  *y1 = this->offset_y;
-  *width = this->width;
-  *height = this->height;
+  // --- 3-Byte Sequence: 1110xxxx 10xxxxxx 10xxxxxx ---
+  else if ((c1 & 0xF0) == 0xE0) {
+    uint8_t c2 = *current++;
+    uint8_t c3 = *current++;
+
+    // Error Check 1: Check continuation bytes
+    if (((c2 & 0xC0) != 0x80) || ((c3 & 0xC0) != 0x80)) {
+      *length = 0;
+      return 0;
+    }
+
+    code_point = (c1 & 0x0F) << 12;
+    code_point |= (c2 & 0x3F) << 6;
+    code_point |= (c3 & 0x3F);
+
+    // Error Check 2: Overlong check (3-byte must be > 0x7FF)
+    // Also check for surrogates (0xD800-0xDFFF)
+    if (code_point <= 0x7FF || (code_point >= 0xD800 && code_point <= 0xDFFF)) {
+      *length = 0;
+      return 0;
+    }
+  }
+  // --- 4-Byte Sequence: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx ---
+  else if ((c1 & 0xF8) == 0xF0) {
+    uint8_t c2 = *current++;
+    uint8_t c3 = *current++;
+    uint8_t c4 = *current++;
+
+    // Error Check 1: Check continuation bytes
+    if (((c2 & 0xC0) != 0x80) || ((c3 & 0xC0) != 0x80) || ((c4 & 0xC0) != 0x80)) {
+      *length = 0;
+      return 0;
+    }
+
+    code_point = (c1 & 0x07) << 18;
+    code_point |= (c2 & 0x3F) << 12;
+    code_point |= (c3 & 0x3F) << 6;
+    code_point |= (c4 & 0x3F);
+
+    // Error Check 2: Overlong check (4-byte must be > 0xFFFF)
+    // Also check for valid Unicode range (must be <= 0x10FFFF)
+    if (code_point <= 0xFFFF || code_point > 0x10FFFF) {
+      *length = 0;
+      return 0;
+    }
+  }
+  // --- Invalid leading byte (e.g., 10xxxxxx or 11111xxx) ---
+  else {
+    *length = 0;
+    return 0;
+  }
+  *length = current - reinterpret_cast<const uint8_t *>(utf8_str);
+  return code_point;
 }
 
 Font::Font(const Glyph *data, int data_nr, int baseline, int height, int descender, int xheight, int capheight,
@@ -53,82 +158,93 @@ Font::Font(const Glyph *data, int data_nr, int baseline, int height, int descend
       linegap_(height - baseline - descender),
       xheight_(xheight),
       capheight_(capheight),
-      bpp_(bpp) {}
-int Font::match_next_glyph(const uint8_t *str, int *match_length) const {
+      bpp_(bpp) {
+#ifdef USE_LVGL_FONT
+  this->lv_font_.dsc = this;
+  this->lv_font_.line_height = this->get_height();
+  this->lv_font_.base_line = this->lv_font_.line_height - this->get_baseline();
+  this->lv_font_.get_glyph_dsc = get_glyph_dsc_cb;
+  this->lv_font_.get_glyph_bitmap = get_glyph_bitmap;
+  this->lv_font_.subpx = LV_FONT_SUBPX_NONE;
+  this->lv_font_.underline_position = -1;
+  this->lv_font_.underline_thickness = 1;
+#endif
+}
+
+const Glyph *Font::find_glyph(uint32_t codepoint) const {
   int lo = 0;
   int hi = this->glyphs_.size() - 1;
   while (lo != hi) {
     int mid = (lo + hi + 1) / 2;
-    if (this->glyphs_[mid].compare_to(str)) {
+    if (this->glyphs_[mid].is_less_or_equal(codepoint)) {
       lo = mid;
     } else {
       hi = mid - 1;
     }
   }
-  *match_length = this->glyphs_[lo].match_length(str);
-  if (*match_length <= 0)
-    return -1;
-  return lo;
+  auto *result = &this->glyphs_[lo];
+  if (result->code_point == codepoint)
+    return result;
+  return nullptr;
 }
+
 #ifdef USE_DISPLAY
 void Font::measure(const char *str, int *width, int *x_offset, int *baseline, int *height) {
   *baseline = this->baseline_;
   *height = this->height_;
-  int i = 0;
   int min_x = 0;
   bool has_char = false;
   int x = 0;
-  while (str[i] != '\0') {
-    int match_length;
-    int glyph_n = this->match_next_glyph((const uint8_t *) str + i, &match_length);
-    if (glyph_n < 0) {
+  for (;;) {
+    size_t length;
+    auto code_point = extract_unicode_codepoint(str, &length);
+    if (length == 0)
+      break;
+    str += length;
+    auto *glyph = this->find_glyph(code_point);
+    if (glyph == nullptr) {
       // Unknown char, skip
-      if (!this->get_glyphs().empty())
-        x += this->get_glyphs()[0].advance;
-      i++;
+      if (!this->glyphs_.empty())
+        x += this->glyphs_[0].advance;
       continue;
     }
 
-    const Glyph &glyph = this->glyphs_[glyph_n];
     if (!has_char) {
-      min_x = glyph.offset_x;
+      min_x = glyph->offset_x;
     } else {
-      min_x = std::min(min_x, x + glyph.offset_x);
+      min_x = std::min(min_x, x + glyph->offset_x);
     }
-    x += glyph.advance;
+    x += glyph->advance;
 
-    i += match_length;
     has_char = true;
   }
   *x_offset = min_x;
   *width = x - min_x;
 }
+
 void Font::print(int x_start, int y_start, display::Display *display, Color color, const char *text, Color background) {
-  int i = 0;
   int x_at = x_start;
-  int scan_x1, scan_y1, scan_width, scan_height;
-  while (text[i] != '\0') {
-    int match_length;
-    int glyph_n = this->match_next_glyph((const uint8_t *) text + i, &match_length);
-    if (glyph_n < 0) {
+  for (;;) {
+    size_t length;
+    auto code_point = extract_unicode_codepoint(text, &length);
+    if (length == 0)
+      break;
+    text += length;
+    auto *glyph = this->find_glyph(code_point);
+    if (glyph == nullptr) {
       // Unknown char, skip
-      ESP_LOGW(TAG, "Encountered character without representation in font: '%c'", text[i]);
-      if (!this->get_glyphs().empty()) {
-        uint8_t glyph_width = this->get_glyphs()[0].advance;
-        display->filled_rectangle(x_at, y_start, glyph_width, this->height_, color);
+      ESP_LOGW(TAG, "Codepoint 0x%08" PRIx32 " not found in font", code_point);
+      if (!this->glyphs_.empty()) {
+        uint8_t glyph_width = this->glyphs_[0].advance;
+        display->rectangle(x_at, y_start, glyph_width, this->height_, color);
         x_at += glyph_width;
       }
-
-      i++;
       continue;
     }
 
-    const Glyph &glyph = this->get_glyphs()[glyph_n];
-    glyph.scan_area(&scan_x1, &scan_y1, &scan_width, &scan_height);
-
-    const uint8_t *data = glyph.data;
-    const int max_x = x_at + scan_x1 + scan_width;
-    const int max_y = y_start + scan_y1 + scan_height;
+    const uint8_t *data = glyph->data;
+    const int max_x = x_at + glyph->offset_x + glyph->width;
+    const int max_y = y_start + glyph->offset_y + glyph->height;
 
     uint8_t bitmask = 0;
     uint8_t pixel_data = 0;
@@ -141,10 +257,10 @@ void Font::print(int x_start, int y_start, display::Display *display, Color colo
     auto b_g = (float) background.g;
     auto b_b = (float) background.b;
     auto b_w = (float) background.w;
-    for (int glyph_y = y_start + scan_y1; glyph_y != max_y; glyph_y++) {
-      for (int glyph_x = x_at + scan_x1; glyph_x != max_x; glyph_x++) {
+    for (int glyph_y = y_start + glyph->offset_y; glyph_y != max_y; glyph_y++) {
+      for (int glyph_x = x_at + glyph->offset_x; glyph_x != max_x; glyph_x++) {
         uint8_t pixel = 0;
-        for (int bit_num = 0; bit_num != this->bpp_; bit_num++) {
+        for (uint8_t bit_num = 0; bit_num != this->bpp_; bit_num++) {
           if (bitmask == 0) {
             pixel_data = progmem_read_byte(data++);
             bitmask = 0x80;
@@ -164,12 +280,9 @@ void Font::print(int x_start, int y_start, display::Display *display, Color colo
         }
       }
     }
-    x_at += glyph.advance;
-
-    i += match_length;
+    x_at += glyph->advance;
   }
 }
 #endif
-
 }  // namespace font
 }  // namespace esphome
diff --git a/esphome/components/font/font.h b/esphome/components/font/font.h
index cb6cc89137..262ded3be4 100644
--- a/esphome/components/font/font.h
+++ b/esphome/components/font/font.h
@@ -6,6 +6,9 @@
 #ifdef USE_DISPLAY
 #include "esphome/components/display/display.h"
 #endif
+#ifdef USE_LVGL_FONT
+#include <lvgl.h>
+#endif
 
 namespace esphome {
 namespace font {
@@ -14,9 +17,9 @@ class Font;
 
 class Glyph {
  public:
-  constexpr Glyph(const char *a_char, const uint8_t *data, int advance, int offset_x, int offset_y, int width,
+  constexpr Glyph(uint32_t code_point, const uint8_t *data, int advance, int offset_x, int offset_y, int width,
                   int height)
-      : a_char(a_char),
+      : code_point(code_point),
         data(data),
         advance(advance),
         offset_x(offset_x),
@@ -24,24 +27,15 @@ class Glyph {
         width(width),
         height(height) {}
 
-  const uint8_t *get_char() const { return reinterpret_cast<const uint8_t *>(this->a_char); }
+  bool is_less_or_equal(uint32_t other) const { return this->code_point <= other; }
 
-  bool compare_to(const uint8_t *str) const;
-
-  int match_length(const uint8_t *str) const;
-
-  void scan_area(int *x1, int *y1, int *width, int *height) const;
-
-  const char *a_char;
+  const uint32_t code_point;
   const uint8_t *data;
   int advance;
   int offset_x;
   int offset_y;
   int width;
   int height;
-
- protected:
-  friend Font;
 };
 
 class Font
@@ -64,7 +58,7 @@ class Font
   Font(const Glyph *data, int data_nr, int baseline, int height, int descender, int xheight, int capheight,
        uint8_t bpp = 1);
 
-  int match_next_glyph(const uint8_t *str, int *match_length) const;
+  const Glyph *find_glyph(uint32_t codepoint) const;
 
 #ifdef USE_DISPLAY
   void print(int x_start, int y_start, display::Display *display, Color color, const char *text,
@@ -79,6 +73,9 @@ class Font
   inline int get_xheight() { return this->xheight_; }
   inline int get_capheight() { return this->capheight_; }
   inline int get_bpp() { return this->bpp_; }
+#ifdef USE_LVGL_FONT
+  const lv_font_t *get_lv_font() const { return &this->lv_font_; }
+#endif
 
   const ConstVector<Glyph> &get_glyphs() const { return glyphs_; }
 
@@ -91,6 +88,14 @@ class Font
   int xheight_;
   int capheight_;
   uint8_t bpp_;  // bits per pixel
+#ifdef USE_LVGL_FONT
+  lv_font_t lv_font_{};
+  static const uint8_t *get_glyph_bitmap(const lv_font_t *font, uint32_t unicode_letter);
+  static bool get_glyph_dsc_cb(const lv_font_t *font, lv_font_glyph_dsc_t *dsc, uint32_t unicode_letter, uint32_t next);
+  const Glyph *get_glyph_data_(uint32_t unicode_letter);
+  uint32_t last_letter_{};
+  const Glyph *last_data_{};
+#endif
 };
 
 }  // namespace font
diff --git a/esphome/components/lvgl/__init__.py b/esphome/components/lvgl/__init__.py
index 2a24f343c3..eaa37b54dd 100644
--- a/esphome/components/lvgl/__init__.py
+++ b/esphome/components/lvgl/__init__.py
@@ -52,15 +52,7 @@ from .schemas import (
 from .styles import add_top_layer, styles_to_code, theme_to_code
 from .touchscreens import touchscreen_schema, touchscreens_to_code
 from .trigger import add_on_boot_triggers, generate_triggers
-from .types import (
-    FontEngine,
-    IdleTrigger,
-    PlainTrigger,
-    lv_font_t,
-    lv_group_t,
-    lv_style_t,
-    lvgl_ns,
-)
+from .types import IdleTrigger, PlainTrigger, lv_font_t, lv_group_t, lv_style_t, lvgl_ns
 from .widgets import (
     LvScrActType,
     Widget,
@@ -244,7 +236,6 @@ async def to_code(configs):
     cg.add_global(lvgl_ns.using)
     for font in helpers.esphome_fonts_used:
         await cg.get_variable(font)
-        cg.new_Pvariable(ID(f"{font}_engine", True, type=FontEngine), MockObj(font))
     default_font = config_0[df.CONF_DEFAULT_FONT]
     if not lvalid.is_lv_font(default_font):
         add_define(
@@ -256,7 +247,8 @@ async def to_code(configs):
             type=lv_font_t.operator("ptr").operator("const"),
         )
         cg.new_variable(
-            globfont_id, MockObj(await lvalid.lv_font.process(default_font))
+            globfont_id,
+            MockObj(await lvalid.lv_font.process(default_font), "->").get_lv_font(),
         )
         add_define("LV_FONT_DEFAULT", df.DEFAULT_ESPHOME_FONT)
     else:
diff --git a/esphome/components/lvgl/font.cpp b/esphome/components/lvgl/font.cpp
deleted file mode 100644
index 1976fb9608..0000000000
--- a/esphome/components/lvgl/font.cpp
+++ /dev/null
@@ -1,76 +0,0 @@
-#include "lvgl_esphome.h"
-
-#ifdef USE_LVGL_FONT
-namespace esphome {
-namespace lvgl {
-
-static const uint8_t *get_glyph_bitmap(const lv_font_t *font, uint32_t unicode_letter) {
-  auto *fe = (FontEngine *) font->dsc;
-  const auto *gd = fe->get_glyph_data(unicode_letter);
-  if (gd == nullptr)
-    return nullptr;
-  // esph_log_d(TAG, "Returning bitmap @  %X", (uint32_t)gd->data);
-
-  return gd->data;
-}
-
-static bool get_glyph_dsc_cb(const lv_font_t *font, lv_font_glyph_dsc_t *dsc, uint32_t unicode_letter, uint32_t next) {
-  auto *fe = (FontEngine *) font->dsc;
-  const auto *gd = fe->get_glyph_data(unicode_letter);
-  if (gd == nullptr)
-    return false;
-  dsc->adv_w = gd->advance;
-  dsc->ofs_x = gd->offset_x;
-  dsc->ofs_y = fe->height - gd->height - gd->offset_y - fe->baseline;
-  dsc->box_w = gd->width;
-  dsc->box_h = gd->height;
-  dsc->is_placeholder = 0;
-  dsc->bpp = fe->bpp;
-  return true;
-}
-
-FontEngine::FontEngine(font::Font *esp_font) : font_(esp_font) {
-  this->bpp = esp_font->get_bpp();
-  this->lv_font_.dsc = this;
-  this->lv_font_.line_height = this->height = esp_font->get_height();
-  this->lv_font_.base_line = this->baseline = this->lv_font_.line_height - esp_font->get_baseline();
-  this->lv_font_.get_glyph_dsc = get_glyph_dsc_cb;
-  this->lv_font_.get_glyph_bitmap = get_glyph_bitmap;
-  this->lv_font_.subpx = LV_FONT_SUBPX_NONE;
-  this->lv_font_.underline_position = -1;
-  this->lv_font_.underline_thickness = 1;
-}
-
-const lv_font_t *FontEngine::get_lv_font() { return &this->lv_font_; }
-
-const font::Glyph *FontEngine::get_glyph_data(uint32_t unicode_letter) {
-  if (unicode_letter == last_letter_)
-    return this->last_data_;
-  uint8_t unicode[5];
-  memset(unicode, 0, sizeof unicode);
-  if (unicode_letter > 0xFFFF) {
-    unicode[0] = 0xF0 + ((unicode_letter >> 18) & 0x7);
-    unicode[1] = 0x80 + ((unicode_letter >> 12) & 0x3F);
-    unicode[2] = 0x80 + ((unicode_letter >> 6) & 0x3F);
-    unicode[3] = 0x80 + (unicode_letter & 0x3F);
-  } else if (unicode_letter > 0x7FF) {
-    unicode[0] = 0xE0 + ((unicode_letter >> 12) & 0xF);
-    unicode[1] = 0x80 + ((unicode_letter >> 6) & 0x3F);
-    unicode[2] = 0x80 + (unicode_letter & 0x3F);
-  } else if (unicode_letter > 0x7F) {
-    unicode[0] = 0xC0 + ((unicode_letter >> 6) & 0x1F);
-    unicode[1] = 0x80 + (unicode_letter & 0x3F);
-  } else {
-    unicode[0] = unicode_letter;
-  }
-  int match_length;
-  int glyph_n = this->font_->match_next_glyph(unicode, &match_length);
-  if (glyph_n < 0)
-    return nullptr;
-  this->last_data_ = &this->font_->get_glyphs()[glyph_n];
-  this->last_letter_ = unicode_letter;
-  return this->last_data_;
-}
-}  // namespace lvgl
-}  // namespace esphome
-#endif  // USES_LVGL_FONT
diff --git a/esphome/components/lvgl/lv_validation.py b/esphome/components/lvgl/lv_validation.py
index 045258555c..23c322c31f 100644
--- a/esphome/components/lvgl/lv_validation.py
+++ b/esphome/components/lvgl/lv_validation.py
@@ -493,6 +493,7 @@ class LvFont(LValidator):
                 return LV_FONTS
             if is_lv_font(value):
                 return lv_builtin_font(value)
+            add_lv_use("font")
             fontval = cv.use_id(Font)(value)
             esphome_fonts_used.add(fontval)
             return requires_component("font")(fontval)
@@ -502,7 +503,9 @@ class LvFont(LValidator):
     async def process(self, value, args=()):
         if is_lv_font(value):
             return literal(f"&lv_font_{value}")
-        return literal(f"{value}_engine->get_lv_font()")
+        if isinstance(value, str):
+            return literal(f"{value}")
+        return await super().process(value, args)
 
 
 lv_font = LvFont()
diff --git a/esphome/components/lvgl/lvgl_esphome.h b/esphome/components/lvgl/lvgl_esphome.h
index 196a0d1cb4..bd6f1fdb61 100644
--- a/esphome/components/lvgl/lvgl_esphome.h
+++ b/esphome/components/lvgl/lvgl_esphome.h
@@ -50,6 +50,14 @@ static const display::ColorBitness LV_BITNESS = display::ColorBitness::COLOR_BIT
 static const display::ColorBitness LV_BITNESS = display::ColorBitness::COLOR_BITNESS_332;
 #endif  // LV_COLOR_DEPTH
 
+#ifdef USE_LVGL_FONT
+inline void lv_obj_set_style_text_font(lv_obj_t *obj, const font::Font *font, lv_style_selector_t part) {
+  lv_obj_set_style_text_font(obj, font->get_lv_font(), part);
+}
+inline void lv_style_set_text_font(lv_style_t *style, const font::Font *font) {
+  lv_style_set_text_font(style, font->get_lv_font());
+}
+#endif
 #ifdef USE_LVGL_IMAGE
 // Shortcut / overload, so that the source of an image can easily be updated
 // from within a lambda.
@@ -134,24 +142,6 @@ template<typename... Ts> class ObjUpdateAction : public Action<Ts...> {
  protected:
   std::function<void(Ts...)> lamb_;
 };
-#ifdef USE_LVGL_FONT
-class FontEngine {
- public:
-  FontEngine(font::Font *esp_font);
-  const lv_font_t *get_lv_font();
-
-  const font::Glyph *get_glyph_data(uint32_t unicode_letter);
-  uint16_t baseline{};
-  uint16_t height{};
-  uint8_t bpp{};
-
- protected:
-  font::Font *font_{};
-  uint32_t last_letter_{};
-  const font::Glyph *last_data_{};
-  lv_font_t lv_font_{};
-};
-#endif  // USE_LVGL_FONT
 #ifdef USE_LVGL_ANIMIMG
 void lv_animimg_stop(lv_obj_t *obj);
 #endif  // USE_LVGL_ANIMIMG
diff --git a/esphome/components/lvgl/types.py b/esphome/components/lvgl/types.py
index 035320b6ac..b99c0ad5a3 100644
--- a/esphome/components/lvgl/types.py
+++ b/esphome/components/lvgl/types.py
@@ -45,7 +45,6 @@ lv_coord_t = cg.global_ns.namespace("lv_coord_t")
 lv_event_code_t = cg.global_ns.enum("lv_event_code_t")
 lv_indev_type_t = cg.global_ns.enum("lv_indev_type_t")
 lv_key_t = cg.global_ns.enum("lv_key_t")
-FontEngine = lvgl_ns.class_("FontEngine")
 PlainTrigger = esphome_ns.class_("Trigger<>", automation.Trigger.template())
 DrawEndTrigger = esphome_ns.class_(
     "Trigger<uint32_t, uint32_t>", automation.Trigger.template(cg.uint32, cg.uint32)
diff --git a/esphome/components/sntp/time.py b/esphome/components/sntp/time.py
index d27fc9991d..69a2436d3d 100644
--- a/esphome/components/sntp/time.py
+++ b/esphome/components/sntp/time.py
@@ -1,9 +1,14 @@
+import logging
+
 import esphome.codegen as cg
 from esphome.components import time as time_
+from esphome.config_helpers import merge_config
 import esphome.config_validation as cv
 from esphome.const import (
     CONF_ID,
+    CONF_PLATFORM,
     CONF_SERVERS,
+    CONF_TIME,
     PLATFORM_BK72XX,
     PLATFORM_ESP32,
     PLATFORM_ESP8266,
@@ -12,13 +17,74 @@ from esphome.const import (
     PLATFORM_RTL87XX,
 )
 from esphome.core import CORE
+import esphome.final_validate as fv
+from esphome.types import ConfigType
+
+_LOGGER = logging.getLogger(__name__)
 
 DEPENDENCIES = ["network"]
+
+CONF_SNTP = "sntp"
+
 sntp_ns = cg.esphome_ns.namespace("sntp")
 SNTPComponent = sntp_ns.class_("SNTPComponent", time_.RealTimeClock)
 
 DEFAULT_SERVERS = ["0.pool.ntp.org", "1.pool.ntp.org", "2.pool.ntp.org"]
 
+
+def _sntp_final_validate(config: ConfigType) -> None:
+    """Merge multiple SNTP instances into one, similar to OTA merging behavior."""
+    full_conf = fv.full_config.get()
+    time_confs = full_conf.get(CONF_TIME, [])
+
+    sntp_configs: list[ConfigType] = []
+    other_time_configs: list[ConfigType] = []
+
+    for time_conf in time_confs:
+        if time_conf.get(CONF_PLATFORM) == CONF_SNTP:
+            sntp_configs.append(time_conf)
+        else:
+            other_time_configs.append(time_conf)
+
+    if len(sntp_configs) <= 1:
+        return
+
+    # Merge all SNTP configs into the first one
+    merged = sntp_configs[0]
+    for sntp_conf in sntp_configs[1:]:
+        # Validate that IDs are consistent if manually specified
+        if merged[CONF_ID].is_manual and sntp_conf[CONF_ID].is_manual:
+            raise cv.Invalid(
+                f"Found multiple SNTP configurations but {CONF_ID} is inconsistent"
+            )
+        merged = merge_config(merged, sntp_conf)
+
+    # Deduplicate servers while preserving order
+    servers = merged[CONF_SERVERS]
+    unique_servers = list(dict.fromkeys(servers))
+
+    # Warn if we're dropping servers due to 3-server limit
+    if len(unique_servers) > 3:
+        dropped = unique_servers[3:]
+        unique_servers = unique_servers[:3]
+        _LOGGER.warning(
+            "SNTP supports maximum 3 servers. Dropped excess server(s): %s",
+            dropped,
+        )
+
+    merged[CONF_SERVERS] = unique_servers
+
+    _LOGGER.warning(
+        "Found and merged %d SNTP time configurations into one instance",
+        len(sntp_configs),
+    )
+
+    # Replace time configs with merged SNTP + other time platforms
+    other_time_configs.append(merged)
+    full_conf[CONF_TIME] = other_time_configs
+    fv.full_config.set(full_conf)
+
+
 CONFIG_SCHEMA = cv.All(
     time_.TIME_SCHEMA.extend(
         {
@@ -40,6 +106,8 @@ CONFIG_SCHEMA = cv.All(
     ),
 )
 
+FINAL_VALIDATE_SCHEMA = _sntp_final_validate
+
 
 async def to_code(config):
     servers = config[CONF_SERVERS]
diff --git a/esphome/components/uart/uart_component_esp8266.cpp b/esphome/components/uart/uart_component_esp8266.cpp
index 7a453dbb50..c84a877ef4 100644
--- a/esphome/components/uart/uart_component_esp8266.cpp
+++ b/esphome/components/uart/uart_component_esp8266.cpp
@@ -56,11 +56,19 @@ uint32_t ESP8266UartComponent::get_config() {
 }
 
 void ESP8266UartComponent::setup() {
-  if (this->rx_pin_) {
-    this->rx_pin_->setup();
-  }
-  if (this->tx_pin_ && this->rx_pin_ != this->tx_pin_) {
-    this->tx_pin_->setup();
+  auto setup_pin_if_needed = [](InternalGPIOPin *pin) {
+    if (!pin) {
+      return;
+    }
+    const auto mask = gpio::Flags::FLAG_OPEN_DRAIN | gpio::Flags::FLAG_PULLUP | gpio::Flags::FLAG_PULLDOWN;
+    if ((pin->get_flags() & mask) != gpio::Flags::FLAG_NONE) {
+      pin->setup();
+    }
+  };
+
+  setup_pin_if_needed(this->rx_pin_);
+  if (this->rx_pin_ != this->tx_pin_) {
+    setup_pin_if_needed(this->tx_pin_);
   }
 
   // Use Arduino HardwareSerial UARTs if all used pins match the ones
diff --git a/esphome/components/uart/uart_component_esp_idf.cpp b/esphome/components/uart/uart_component_esp_idf.cpp
index 70a13c9e37..61ca8c1c0c 100644
--- a/esphome/components/uart/uart_component_esp_idf.cpp
+++ b/esphome/components/uart/uart_component_esp_idf.cpp
@@ -133,11 +133,19 @@ void IDFUARTComponent::load_settings(bool dump_config) {
     return;
   }
 
-  if (this->rx_pin_) {
-    this->rx_pin_->setup();
-  }
-  if (this->tx_pin_ && this->rx_pin_ != this->tx_pin_) {
-    this->tx_pin_->setup();
+  auto setup_pin_if_needed = [](InternalGPIOPin *pin) {
+    if (!pin) {
+      return;
+    }
+    const auto mask = gpio::Flags::FLAG_OPEN_DRAIN | gpio::Flags::FLAG_PULLUP | gpio::Flags::FLAG_PULLDOWN;
+    if ((pin->get_flags() & mask) != gpio::Flags::FLAG_NONE) {
+      pin->setup();
+    }
+  };
+
+  setup_pin_if_needed(this->rx_pin_);
+  if (this->rx_pin_ != this->tx_pin_) {
+    setup_pin_if_needed(this->tx_pin_);
   }
 
   int8_t tx = this->tx_pin_ != nullptr ? this->tx_pin_->get_pin() : -1;
diff --git a/esphome/components/uart/uart_component_libretiny.cpp b/esphome/components/uart/uart_component_libretiny.cpp
index 8d1d28fce4..1e408b169b 100644
--- a/esphome/components/uart/uart_component_libretiny.cpp
+++ b/esphome/components/uart/uart_component_libretiny.cpp
@@ -53,7 +53,7 @@ void LibreTinyUARTComponent::setup() {
 
   auto shouldFallbackToSoftwareSerial = [&]() -> bool {
     auto hasFlags = [](InternalGPIOPin *pin, const gpio::Flags mask) -> bool {
-      return pin && pin->get_flags() & mask != gpio::Flags::FLAG_NONE;
+      return pin && (pin->get_flags() & mask) != gpio::Flags::FLAG_NONE;
     };
     if (hasFlags(this->tx_pin_, gpio::Flags::FLAG_OPEN_DRAIN | gpio::Flags::FLAG_PULLUP | gpio::Flags::FLAG_PULLDOWN) ||
         hasFlags(this->rx_pin_, gpio::Flags::FLAG_OPEN_DRAIN | gpio::Flags::FLAG_PULLUP | gpio::Flags::FLAG_PULLDOWN)) {
diff --git a/esphome/components/uart/uart_component_rp2040.cpp b/esphome/components/uart/uart_component_rp2040.cpp
index c78691653d..cd3905b5c1 100644
--- a/esphome/components/uart/uart_component_rp2040.cpp
+++ b/esphome/components/uart/uart_component_rp2040.cpp
@@ -52,11 +52,19 @@ uint16_t RP2040UartComponent::get_config() {
 }
 
 void RP2040UartComponent::setup() {
-  if (this->rx_pin_) {
-    this->rx_pin_->setup();
-  }
-  if (this->tx_pin_ && this->rx_pin_ != this->tx_pin_) {
-    this->tx_pin_->setup();
+  auto setup_pin_if_needed = [](InternalGPIOPin *pin) {
+    if (!pin) {
+      return;
+    }
+    const auto mask = gpio::Flags::FLAG_OPEN_DRAIN | gpio::Flags::FLAG_PULLUP | gpio::Flags::FLAG_PULLDOWN;
+    if ((pin->get_flags() & mask) != gpio::Flags::FLAG_NONE) {
+      pin->setup();
+    }
+  };
+
+  setup_pin_if_needed(this->rx_pin_);
+  if (this->rx_pin_ != this->tx_pin_) {
+    setup_pin_if_needed(this->tx_pin_);
   }
 
   uint16_t config = get_config();
diff --git a/esphome/components/web_server/ota/__init__.py b/esphome/components/web_server/ota/__init__.py
index 4a98db8877..260e6aea6d 100644
--- a/esphome/components/web_server/ota/__init__.py
+++ b/esphome/components/web_server/ota/__init__.py
@@ -1,10 +1,17 @@
+import logging
+
 import esphome.codegen as cg
 from esphome.components.esp32 import add_idf_component
 from esphome.components.ota import BASE_OTA_SCHEMA, OTAComponent, ota_to_code
+from esphome.config_helpers import merge_config
 import esphome.config_validation as cv
-from esphome.const import CONF_ID
+from esphome.const import CONF_ID, CONF_OTA, CONF_PLATFORM, CONF_WEB_SERVER
 from esphome.core import CORE, coroutine_with_priority
 from esphome.coroutine import CoroPriority
+import esphome.final_validate as fv
+from esphome.types import ConfigType
+
+_LOGGER = logging.getLogger(__name__)
 
 CODEOWNERS = ["@esphome/core"]
 DEPENDENCIES = ["network", "web_server_base"]
@@ -12,6 +19,53 @@ DEPENDENCIES = ["network", "web_server_base"]
 web_server_ns = cg.esphome_ns.namespace("web_server")
 WebServerOTAComponent = web_server_ns.class_("WebServerOTAComponent", OTAComponent)
 
+
+def _web_server_ota_final_validate(config: ConfigType) -> None:
+    """Merge multiple web_server OTA instances into one.
+
+    Multiple web_server OTA instances register duplicate HTTP handlers for /update,
+    causing undefined behavior. Merge them into a single instance.
+    """
+    full_conf = fv.full_config.get()
+    ota_confs = full_conf.get(CONF_OTA, [])
+
+    web_server_ota_configs: list[ConfigType] = []
+    other_ota_configs: list[ConfigType] = []
+
+    for ota_conf in ota_confs:
+        if ota_conf.get(CONF_PLATFORM) == CONF_WEB_SERVER:
+            web_server_ota_configs.append(ota_conf)
+        else:
+            other_ota_configs.append(ota_conf)
+
+    if len(web_server_ota_configs) <= 1:
+        return
+
+    # Merge all web_server OTA configs into the first one
+    merged = web_server_ota_configs[0]
+    for ota_conf in web_server_ota_configs[1:]:
+        # Validate that IDs are consistent if manually specified
+        if (
+            merged[CONF_ID].is_manual
+            and ota_conf[CONF_ID].is_manual
+            and merged[CONF_ID] != ota_conf[CONF_ID]
+        ):
+            raise cv.Invalid(
+                f"Found multiple web_server OTA configurations but {CONF_ID} is inconsistent"
+            )
+        merged = merge_config(merged, ota_conf)
+
+    _LOGGER.warning(
+        "Found and merged %d web_server OTA configurations into one instance",
+        len(web_server_ota_configs),
+    )
+
+    # Replace OTA configs with merged web_server + other OTA platforms
+    other_ota_configs.append(merged)
+    full_conf[CONF_OTA] = other_ota_configs
+    fv.full_config.set(full_conf)
+
+
 CONFIG_SCHEMA = (
     cv.Schema(
         {
@@ -22,6 +76,8 @@ CONFIG_SCHEMA = (
     .extend(cv.COMPONENT_SCHEMA)
 )
 
+FINAL_VALIDATE_SCHEMA = _web_server_ota_final_validate
+
 
 @coroutine_with_priority(CoroPriority.WEB_SERVER_OTA)
 async def to_code(config):
diff --git a/esphome/components/web_server_idf/web_server_idf.cpp b/esphome/components/web_server_idf/web_server_idf.cpp
index 0dab5e7e8c..ce91569de2 100644
--- a/esphome/components/web_server_idf/web_server_idf.cpp
+++ b/esphome/components/web_server_idf/web_server_idf.cpp
@@ -489,10 +489,18 @@ AsyncEventSourceResponse::AsyncEventSourceResponse(const AsyncWebServerRequest *
 
 void AsyncEventSourceResponse::destroy(void *ptr) {
   auto *rsp = static_cast<AsyncEventSourceResponse *>(ptr);
-  ESP_LOGD(TAG, "Event source connection closed (fd: %d)", rsp->fd_.load());
-  // Mark as dead by setting fd to 0 - will be cleaned up in the main loop
-  rsp->fd_.store(0);
-  // Note: We don't delete or remove from set here to avoid race conditions
+  int fd = rsp->fd_.exchange(0);  // Atomically get and clear fd
+
+  if (fd > 0) {
+    ESP_LOGD(TAG, "Event source connection closed (fd: %d)", fd);
+    // Immediately shut down the socket to prevent lwIP from delivering more data
+    // This prevents "recv_tcp: recv for wrong pcb!" assertions when the TCP stack
+    // tries to deliver queued data after the session is marked as dead
+    // See: https://github.com/esphome/esphome/issues/11936
+    shutdown(fd, SHUT_RDWR);
+    // Note: We don't close() the socket - httpd owns it and will close it
+  }
+  // Session will be cleaned up in the main loop to avoid race conditions
 }
 
 // helper for allowing only unique entries in the queue
diff --git a/esphome/config.py b/esphome/config.py
index e508ca585b..4c8019de75 100644
--- a/esphome/config.py
+++ b/esphome/config.py
@@ -338,21 +338,44 @@ def check_replaceme(value):
         )
 
 
-def _build_list_index(lst):
+def _get_item_id(item: Any) -> str | Extend | Remove | None:
+    """Attempts to get a list item's ID"""
+    if not isinstance(item, dict):
+        return None  # not a dict, can't have ID
+    # 1.- Check regular case:
+    # - id: my_id
+    item_id = item.get(CONF_ID)
+    if item_id is None and len(item) == 1:
+        # 2.- Check single-key dict case:
+        # - obj:
+        #     id: my_id
+        item = next(iter(item.values()))
+        if isinstance(item, dict):
+            item_id = item.get(CONF_ID)
+    if isinstance(item_id, Extend):
+        # Remove instances of Extend so they don't overwrite the original item when merging:
+        del item[CONF_ID]
+    return item_id
+
+
+def _build_list_index(
+    lst: list[Any],
+) -> tuple[
+    OrderedDict[str | Extend | Remove, Any], list[tuple[int, str, Any]], set[str]
+]:
     index = OrderedDict()
     extensions, removals = [], set()
-    for item in lst:
+    for pos, item in enumerate(lst):
         if item is None:
             removals.add(None)
             continue
-        item_id = None
-        if isinstance(item, dict) and (item_id := item.get(CONF_ID)):
-            if isinstance(item_id, Extend):
-                extensions.append(item)
-                continue
-            if isinstance(item_id, Remove):
-                removals.add(item_id.value)
-                continue
+        item_id = _get_item_id(item)
+        if isinstance(item_id, Extend):
+            extensions.append((pos, item_id.value, item))
+            continue
+        if isinstance(item_id, Remove):
+            removals.add(item_id.value)
+            continue
         if not item_id or item_id in index:
             # no id or duplicate -> pass through with identity-based key
             item_id = id(item)
@@ -360,7 +383,7 @@ def _build_list_index(lst):
     return index, extensions, removals
 
 
-def resolve_extend_remove(value, is_key=None):
+def resolve_extend_remove(value: Any, is_key: bool = False) -> None:
     if isinstance(value, ESPLiteralValue):
         return  # do not check inside literal blocks
     if isinstance(value, list):
@@ -368,26 +391,16 @@ def resolve_extend_remove(value, is_key=None):
         if extensions or removals:
             # Rebuild the original list after
             # processing all extensions and removals
-            for item in extensions:
-                item_id = item[CONF_ID].value
+            for pos, item_id, item in extensions:
                 if item_id in removals:
                     continue
                 old = index.get(item_id)
                 if old is None:
                     # Failed to find source for extension
-                    # Find index of item to show error at correct position
-                    i = next(
-                        (
-                            i
-                            for i, d in enumerate(value)
-                            if d.get(CONF_ID) == item[CONF_ID]
-                        )
-                    )
-                    with cv.prepend_path(i):
+                    with cv.prepend_path(pos):
                         raise cv.Invalid(
                             f"Source for extension of ID '{item_id}' was not found."
                         )
-                item[CONF_ID] = item_id
                 index[item_id] = merge_config(old, item)
             for item_id in removals:
                 index.pop(item_id, None)
diff --git a/esphome/const.py b/esphome/const.py
index a25114d80e..b4cd3cfd1c 100644
--- a/esphome/const.py
+++ b/esphome/const.py
@@ -336,6 +336,7 @@ CONF_ENERGY = "energy"
 CONF_ENTITY_CATEGORY = "entity_category"
 CONF_ENTITY_ID = "entity_id"
 CONF_ENUM_DATAPOINT = "enum_datapoint"
+CONF_ENVIRONMENT_VARIABLES = "environment_variables"
 CONF_EQUATION = "equation"
 CONF_ESP8266_DISABLE_SSL_SUPPORT = "esp8266_disable_ssl_support"
 CONF_ESPHOME = "esphome"
diff --git a/esphome/core/config.py b/esphome/core/config.py
index 763f9ebd9f..0a239c5f5e 100644
--- a/esphome/core/config.py
+++ b/esphome/core/config.py
@@ -17,6 +17,7 @@ from esphome.const import (
     CONF_COMPILE_PROCESS_LIMIT,
     CONF_DEBUG_SCHEDULER,
     CONF_DEVICES,
+    CONF_ENVIRONMENT_VARIABLES,
     CONF_ESPHOME,
     CONF_FRIENDLY_NAME,
     CONF_ID,
@@ -215,6 +216,11 @@ CONFIG_SCHEMA = cv.All(
                     cv.string_strict: cv.Any([cv.string], cv.string),
                 }
             ),
+            cv.Optional(CONF_ENVIRONMENT_VARIABLES, default={}): cv.Schema(
+                {
+                    cv.string_strict: cv.string,
+                }
+            ),
             cv.Optional(CONF_ON_BOOT): automation.validate_automation(
                 {
                     cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(StartupTrigger),
@@ -426,6 +432,12 @@ async def _add_platformio_options(pio_options):
         cg.add_platformio_option(key, val)
 
 
+@coroutine_with_priority(CoroPriority.FINAL)
+async def _add_environment_variables(env_vars: dict[str, str]) -> None:
+    # Set environment variables for the build process
+    os.environ.update(env_vars)
+
+
 @coroutine_with_priority(CoroPriority.AUTOMATION)
 async def _add_automations(config):
     for conf in config.get(CONF_ON_BOOT, []):
@@ -563,6 +575,9 @@ async def to_code(config: ConfigType) -> None:
     if config[CONF_PLATFORMIO_OPTIONS]:
         CORE.add_job(_add_platformio_options, config[CONF_PLATFORMIO_OPTIONS])
 
+    if config[CONF_ENVIRONMENT_VARIABLES]:
+        CORE.add_job(_add_environment_variables, config[CONF_ENVIRONMENT_VARIABLES])
+
     # Process areas
     all_areas: list[dict[str, str | core.ID]] = []
     if CONF_AREA in config:
diff --git a/tests/component_tests/ota/test_web_server_ota.py b/tests/component_tests/ota/test_web_server_ota.py
index 0d8ff6f134..794eaac9be 100644
--- a/tests/component_tests/ota/test_web_server_ota.py
+++ b/tests/component_tests/ota/test_web_server_ota.py
@@ -1,6 +1,18 @@
 """Tests for the web_server OTA platform."""
 
+from __future__ import annotations
+
 from collections.abc import Callable
+import logging
+from typing import Any
+
+import pytest
+
+from esphome import config_validation as cv
+from esphome.components.web_server.ota import _web_server_ota_final_validate
+from esphome.const import CONF_ID, CONF_OTA, CONF_PLATFORM, CONF_WEB_SERVER
+from esphome.core import ID
+import esphome.final_validate as fv
 
 
 def test_web_server_ota_generated(generate_main: Callable[[str], str]) -> None:
@@ -100,3 +112,144 @@ def test_web_server_ota_esp8266(generate_main: Callable[[str], str]) -> None:
     # Check web server OTA component is present
     assert "WebServerOTAComponent" in main_cpp
     assert "web_server::WebServerOTAComponent" in main_cpp
+
+
+@pytest.mark.parametrize(
+    ("ota_configs", "expected_count", "warning_expected"),
+    [
+        pytest.param(
+            [
+                {
+                    CONF_PLATFORM: CONF_WEB_SERVER,
+                    CONF_ID: ID("ota_web", is_manual=False),
+                }
+            ],
+            1,
+            False,
+            id="single_instance_no_merge",
+        ),
+        pytest.param(
+            [
+                {
+                    CONF_PLATFORM: CONF_WEB_SERVER,
+                    CONF_ID: ID("ota_web_1", is_manual=False),
+                },
+                {
+                    CONF_PLATFORM: CONF_WEB_SERVER,
+                    CONF_ID: ID("ota_web_2", is_manual=False),
+                },
+            ],
+            1,
+            True,
+            id="two_instances_merged",
+        ),
+        pytest.param(
+            [
+                {
+                    CONF_PLATFORM: CONF_WEB_SERVER,
+                    CONF_ID: ID("ota_web_1", is_manual=False),
+                },
+                {
+                    CONF_PLATFORM: "esphome",
+                    CONF_ID: ID("ota_esphome", is_manual=False),
+                },
+                {
+                    CONF_PLATFORM: CONF_WEB_SERVER,
+                    CONF_ID: ID("ota_web_2", is_manual=False),
+                },
+            ],
+            2,
+            True,
+            id="mixed_platforms_web_server_merged",
+        ),
+    ],
+)
+def test_web_server_ota_instance_merging(
+    ota_configs: list[dict[str, Any]],
+    expected_count: int,
+    warning_expected: bool,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test web_server OTA instance merging behavior."""
+    full_conf = {CONF_OTA: ota_configs.copy()}
+
+    token = fv.full_config.set(full_conf)
+    try:
+        with caplog.at_level(logging.WARNING):
+            _web_server_ota_final_validate({})
+
+        updated_conf = fv.full_config.get()
+
+        # Verify total number of OTA platforms
+        assert len(updated_conf[CONF_OTA]) == expected_count
+
+        # Verify warning
+        if warning_expected:
+            assert any(
+                "Found and merged" in record.message
+                and "web_server OTA" in record.message
+                for record in caplog.records
+            ), "Expected merge warning not found in log"
+        else:
+            assert len(caplog.records) == 0, "Unexpected warnings logged"
+    finally:
+        fv.full_config.reset(token)
+
+
+def test_web_server_ota_consistent_manual_ids(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test that consistent manual IDs can be merged successfully."""
+    ota_configs = [
+        {
+            CONF_PLATFORM: CONF_WEB_SERVER,
+            CONF_ID: ID("ota_web", is_manual=True),
+        },
+        {
+            CONF_PLATFORM: CONF_WEB_SERVER,
+            CONF_ID: ID("ota_web", is_manual=True),
+        },
+    ]
+
+    full_conf = {CONF_OTA: ota_configs}
+
+    token = fv.full_config.set(full_conf)
+    try:
+        with caplog.at_level(logging.WARNING):
+            _web_server_ota_final_validate({})
+
+        updated_conf = fv.full_config.get()
+        assert len(updated_conf[CONF_OTA]) == 1
+        assert updated_conf[CONF_OTA][0][CONF_ID].id == "ota_web"
+        assert any(
+            "Found and merged" in record.message and "web_server OTA" in record.message
+            for record in caplog.records
+        )
+    finally:
+        fv.full_config.reset(token)
+
+
+def test_web_server_ota_inconsistent_manual_ids() -> None:
+    """Test that inconsistent manual IDs raise an error."""
+    ota_configs = [
+        {
+            CONF_PLATFORM: CONF_WEB_SERVER,
+            CONF_ID: ID("ota_web_1", is_manual=True),
+        },
+        {
+            CONF_PLATFORM: CONF_WEB_SERVER,
+            CONF_ID: ID("ota_web_2", is_manual=True),
+        },
+    ]
+
+    full_conf = {CONF_OTA: ota_configs}
+
+    token = fv.full_config.set(full_conf)
+    try:
+        with pytest.raises(
+            cv.Invalid,
+            match="Found multiple web_server OTA configurations but id is inconsistent",
+        ):
+            _web_server_ota_final_validate({})
+    finally:
+        fv.full_config.reset(token)
diff --git a/tests/component_tests/sntp/__init__.py b/tests/component_tests/sntp/__init__.py
new file mode 100644
index 0000000000..7d323a4980
--- /dev/null
+++ b/tests/component_tests/sntp/__init__.py
@@ -0,0 +1 @@
+"""Tests for SNTP component."""
diff --git a/tests/component_tests/sntp/config/sntp_test.yaml b/tests/component_tests/sntp/config/sntp_test.yaml
new file mode 100644
index 0000000000..3942c9606b
--- /dev/null
+++ b/tests/component_tests/sntp/config/sntp_test.yaml
@@ -0,0 +1,22 @@
+esphome:
+  name: sntp-test
+
+esp32:
+  board: esp32dev
+  framework:
+    type: esp-idf
+
+wifi:
+  ssid: "testssid"
+  password: "testpassword"
+
+# Test multiple SNTP instances that should be merged
+time:
+  - platform: sntp
+    servers:
+      - 192.168.1.1
+      - pool.ntp.org
+  - platform: sntp
+    servers:
+      - pool.ntp.org
+      - 192.168.1.2
diff --git a/tests/component_tests/sntp/test_init.py b/tests/component_tests/sntp/test_init.py
new file mode 100644
index 0000000000..9197ff55d0
--- /dev/null
+++ b/tests/component_tests/sntp/test_init.py
@@ -0,0 +1,238 @@
+"""Tests for SNTP time configuration validation."""
+
+from __future__ import annotations
+
+import logging
+from typing import Any
+
+import pytest
+
+from esphome import config_validation as cv
+from esphome.components.sntp.time import CONF_SNTP, _sntp_final_validate
+from esphome.const import CONF_ID, CONF_PLATFORM, CONF_SERVERS, CONF_TIME
+from esphome.core import ID
+import esphome.final_validate as fv
+
+
+@pytest.mark.parametrize(
+    ("time_configs", "expected_count", "expected_servers", "warning_messages"),
+    [
+        pytest.param(
+            [
+                {
+                    CONF_PLATFORM: CONF_SNTP,
+                    CONF_ID: ID("sntp_time", is_manual=False),
+                    CONF_SERVERS: ["192.168.1.1", "pool.ntp.org"],
+                }
+            ],
+            1,
+            ["192.168.1.1", "pool.ntp.org"],
+            [],
+            id="single_instance_no_merge",
+        ),
+        pytest.param(
+            [
+                {
+                    CONF_PLATFORM: CONF_SNTP,
+                    CONF_ID: ID("sntp_time_1", is_manual=False),
+                    CONF_SERVERS: ["192.168.1.1", "pool.ntp.org"],
+                },
+                {
+                    CONF_PLATFORM: CONF_SNTP,
+                    CONF_ID: ID("sntp_time_2", is_manual=False),
+                    CONF_SERVERS: ["192.168.1.2"],
+                },
+            ],
+            1,
+            ["192.168.1.1", "pool.ntp.org", "192.168.1.2"],
+            ["Found and merged 2 SNTP time configurations into one instance"],
+            id="two_instances_merged",
+        ),
+        pytest.param(
+            [
+                {
+                    CONF_PLATFORM: CONF_SNTP,
+                    CONF_ID: ID("sntp_time_1", is_manual=False),
+                    CONF_SERVERS: ["192.168.1.1", "pool.ntp.org"],
+                },
+                {
+                    CONF_PLATFORM: CONF_SNTP,
+                    CONF_ID: ID("sntp_time_2", is_manual=False),
+                    CONF_SERVERS: ["pool.ntp.org", "192.168.1.2"],
+                },
+            ],
+            1,
+            ["192.168.1.1", "pool.ntp.org", "192.168.1.2"],
+            ["Found and merged 2 SNTP time configurations into one instance"],
+            id="deduplication_preserves_order",
+        ),
+        pytest.param(
+            [
+                {
+                    CONF_PLATFORM: CONF_SNTP,
+                    CONF_ID: ID("sntp_time_1", is_manual=False),
+                    CONF_SERVERS: ["192.168.1.1", "pool.ntp.org"],
+                },
+                {
+                    CONF_PLATFORM: CONF_SNTP,
+                    CONF_ID: ID("sntp_time_2", is_manual=False),
+                    CONF_SERVERS: ["192.168.1.2", "pool2.ntp.org"],
+                },
+                {
+                    CONF_PLATFORM: CONF_SNTP,
+                    CONF_ID: ID("sntp_time_3", is_manual=False),
+                    CONF_SERVERS: ["pool3.ntp.org"],
+                },
+            ],
+            1,
+            ["192.168.1.1", "pool.ntp.org", "192.168.1.2"],
+            [
+                "SNTP supports maximum 3 servers. Dropped excess server(s): ['pool2.ntp.org', 'pool3.ntp.org']",
+                "Found and merged 3 SNTP time configurations into one instance",
+            ],
+            id="three_instances_drops_excess_servers",
+        ),
+        pytest.param(
+            [
+                {
+                    CONF_PLATFORM: CONF_SNTP,
+                    CONF_ID: ID("sntp_time_1", is_manual=False),
+                    CONF_SERVERS: [
+                        "192.168.1.1",
+                        "pool.ntp.org",
+                        "pool.ntp.org",
+                        "192.168.1.1",
+                    ],
+                },
+                {
+                    CONF_PLATFORM: CONF_SNTP,
+                    CONF_ID: ID("sntp_time_2", is_manual=False),
+                    CONF_SERVERS: ["pool.ntp.org", "192.168.1.2"],
+                },
+            ],
+            1,
+            ["192.168.1.1", "pool.ntp.org", "192.168.1.2"],
+            ["Found and merged 2 SNTP time configurations into one instance"],
+            id="deduplication_multiple_duplicates",
+        ),
+    ],
+)
+def test_sntp_instance_merging(
+    time_configs: list[dict[str, Any]],
+    expected_count: int,
+    expected_servers: list[str],
+    warning_messages: list[str],
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test SNTP instance merging behavior."""
+    # Create a mock full config with time configs
+    full_conf = {CONF_TIME: time_configs.copy()}
+
+    # Set the context var
+    token = fv.full_config.set(full_conf)
+    try:
+        with caplog.at_level(logging.WARNING):
+            _sntp_final_validate({})
+
+        # Get the updated config
+        updated_conf = fv.full_config.get()
+
+        # Check if merging occurred
+        if len(time_configs) > 1:
+            # Verify only one SNTP instance remains
+            sntp_instances = [
+                tc
+                for tc in updated_conf[CONF_TIME]
+                if tc.get(CONF_PLATFORM) == CONF_SNTP
+            ]
+            assert len(sntp_instances) == expected_count
+
+            # Verify server list
+            assert sntp_instances[0][CONF_SERVERS] == expected_servers
+
+            # Verify warnings
+            for expected_msg in warning_messages:
+                assert any(
+                    expected_msg in record.message for record in caplog.records
+                ), f"Expected warning message '{expected_msg}' not found in log"
+        else:
+            # Single instance should not trigger merging or warnings
+            assert len(caplog.records) == 0
+            # Config should be unchanged
+            assert updated_conf[CONF_TIME] == time_configs
+    finally:
+        fv.full_config.reset(token)
+
+
+def test_sntp_inconsistent_manual_ids() -> None:
+    """Test that inconsistent manual IDs raise an error."""
+    # Create configs with manual IDs that are inconsistent
+    time_configs = [
+        {
+            CONF_PLATFORM: CONF_SNTP,
+            CONF_ID: ID("sntp_time_1", is_manual=True),
+            CONF_SERVERS: ["192.168.1.1"],
+        },
+        {
+            CONF_PLATFORM: CONF_SNTP,
+            CONF_ID: ID("sntp_time_2", is_manual=True),
+            CONF_SERVERS: ["192.168.1.2"],
+        },
+    ]
+
+    full_conf = {CONF_TIME: time_configs}
+
+    token = fv.full_config.set(full_conf)
+    try:
+        with pytest.raises(
+            cv.Invalid,
+            match="Found multiple SNTP configurations but id is inconsistent",
+        ):
+            _sntp_final_validate({})
+    finally:
+        fv.full_config.reset(token)
+
+
+def test_sntp_with_other_time_platforms(caplog: pytest.LogCaptureFixture) -> None:
+    """Test that SNTP merging doesn't affect other time platforms."""
+    time_configs = [
+        {
+            CONF_PLATFORM: CONF_SNTP,
+            CONF_ID: ID("sntp_time_1", is_manual=False),
+            CONF_SERVERS: ["192.168.1.1"],
+        },
+        {
+            CONF_PLATFORM: "homeassistant",
+            CONF_ID: ID("homeassistant_time", is_manual=False),
+        },
+        {
+            CONF_PLATFORM: CONF_SNTP,
+            CONF_ID: ID("sntp_time_2", is_manual=False),
+            CONF_SERVERS: ["192.168.1.2"],
+        },
+    ]
+
+    full_conf = {CONF_TIME: time_configs.copy()}
+
+    token = fv.full_config.set(full_conf)
+    try:
+        with caplog.at_level(logging.WARNING):
+            _sntp_final_validate({})
+
+        updated_conf = fv.full_config.get()
+
+        # Should have 2 time platforms: 1 merged SNTP + 1 homeassistant
+        assert len(updated_conf[CONF_TIME]) == 2
+
+        # Find the platforms
+        platforms = {tc[CONF_PLATFORM] for tc in updated_conf[CONF_TIME]}
+        assert platforms == {CONF_SNTP, "homeassistant"}
+
+        # Verify SNTP was merged
+        sntp_instances = [
+            tc for tc in updated_conf[CONF_TIME] if tc[CONF_PLATFORM] == CONF_SNTP
+        ]
+        assert len(sntp_instances) == 1
+        assert sntp_instances[0][CONF_SERVERS] == ["192.168.1.1", "192.168.1.2"]
+    finally:
+        fv.full_config.reset(token)
diff --git a/tests/components/esphome/common.yaml b/tests/components/esphome/common.yaml
index b2d7bccaa5..db75b08b38 100644
--- a/tests/components/esphome/common.yaml
+++ b/tests/components/esphome/common.yaml
@@ -2,6 +2,9 @@ esphome:
   debug_scheduler: true
   platformio_options:
     board_build.flash_mode: dio
+  environment_variables:
+    TEST_ENV_VAR: "test_value"
+    BUILD_NUMBER: "12345"
   area:
     id: testing_area
     name: Testing Area
diff --git a/tests/components/lvgl/lvgl-package.yaml b/tests/components/lvgl/lvgl-package.yaml
index d7c342b16e..e42a813b40 100644
--- a/tests/components/lvgl/lvgl-package.yaml
+++ b/tests/components/lvgl/lvgl-package.yaml
@@ -76,7 +76,7 @@ lvgl:
       line_width: 8
       line_rounded: true
     - id: date_style
-      text_font: roboto10
+      text_font: !lambda return id(roboto10);
       align: center
       text_color: !lambda return color_id2;
       bg_opa: cover
@@ -267,7 +267,7 @@ lvgl:
               snprintf(buf, sizeof(buf), "Setup: %d", 42);
               return std::string(buf);
             align: top_mid
-            text_font: space16
+            text_font: !lambda return id(space16);
         - label:
             id: chip_info_label
             # Test complex setup lambda (real-world pattern)
diff --git a/tests/components/lvgl/test.host.yaml b/tests/components/lvgl/test.host.yaml
index 39d9a0ebf3..00a8cd8c01 100644
--- a/tests/components/lvgl/test.host.yaml
+++ b/tests/components/lvgl/test.host.yaml
@@ -18,6 +18,7 @@ touchscreen:
 
 lvgl:
   - id: lvgl_0
+    default_font: space16
     displays: sdl0
   - id: lvgl_1
     displays: sdl1
@@ -39,3 +40,8 @@ lvgl:
                 text: Click ME
           on_click:
             logger.log: Clicked
+
+font:
+  - file: "gfonts://Roboto"
+    id: space16
+    bpp: 4
diff --git a/tests/unit_tests/fixtures/substitutions/05-extend-remove.approved.yaml b/tests/unit_tests/fixtures/substitutions/05-extend-remove.approved.yaml
index a479370f4b..35e3e6258f 100644
--- a/tests/unit_tests/fixtures/substitutions/05-extend-remove.approved.yaml
+++ b/tests/unit_tests/fixtures/substitutions/05-extend-remove.approved.yaml
@@ -7,3 +7,27 @@ some_component:
     value: 2
   - id: component2
     value: 5
+lvgl:
+  pages:
+    - id: page1
+      widgets:
+        - obj:
+            id: object1
+            x: 3
+            y: 2
+            width: 4
+        - obj:
+            id: object3
+            x: 6
+            y: 12
+            widgets:
+              - obj:
+                  id: object4
+                  x: 14
+                  y: 9
+                  width: 15
+            height: 13
+        - obj:
+            id: object5
+            x: 10
+            y: 11
diff --git a/tests/unit_tests/fixtures/substitutions/05-extend-remove.input.yaml b/tests/unit_tests/fixtures/substitutions/05-extend-remove.input.yaml
index 2e0e60798d..617f09c31c 100644
--- a/tests/unit_tests/fixtures/substitutions/05-extend-remove.input.yaml
+++ b/tests/unit_tests/fixtures/substitutions/05-extend-remove.input.yaml
@@ -13,6 +13,30 @@ packages:
         value: 5
       - id: component3
         value: 6
+  - lvgl:
+      pages:
+        - id: page1
+          widgets:
+            - obj:
+                id: object1
+                x: 1
+                y: 2
+            - obj:
+                id: object2
+                x: 5
+            - obj:
+                id: object3
+                x: 6
+                y: 7
+                widgets:
+                  - obj:
+                      id: object4
+                      x: 8
+                      y: 9
+            - obj:
+                id: object5
+                x: 10
+                y: 11
 
 some_component:
   - id: !extend ${A}
@@ -20,3 +44,23 @@ some_component:
   - id: component2
     value: 3
   - id: !remove ${C}
+
+lvgl:
+  pages:
+    - id: !extend page1
+      widgets:
+        - obj:
+            id: !extend object1
+            x: 3
+            width: 4
+        - obj:
+            id: !remove object2
+        - obj:
+            id: !extend object3
+            y: 12
+            height: 13
+            widgets:
+              - obj:
+                  id: !extend object4
+                  x: 14
+                  width: 15