diff --git a/esphome/components/lvgl/defines.py b/esphome/components/lvgl/defines.py
index 1d528b2f73..91077a1ff4 100644
--- a/esphome/components/lvgl/defines.py
+++ b/esphome/components/lvgl/defines.py
@@ -5,7 +5,7 @@ Constants already defined in esphome.const are not duplicated here and must be i
 """
 
 import logging
-from typing import TYPE_CHECKING, Any
+from typing import Any
 
 from esphome import codegen as cg, config_validation as cv
 from esphome.const import CONF_ITEMS
@@ -96,13 +96,9 @@ class LValidator:
             return None
         if isinstance(value, Lambda):
             # Local import to avoid circular import
-            from .lvcode import CodeContext, LambdaContext
+            from .lvcode import get_lambda_context_args
 
-            if TYPE_CHECKING:
-                # CodeContext does not have get_automation_parameters
-                # so we need to assert the type here
-                assert isinstance(CodeContext.code_context, LambdaContext)
-            args = args or CodeContext.code_context.get_automation_parameters()
+            args = args or get_lambda_context_args()
             return cg.RawExpression(
                 call_lambda(
                     await cg.process_lambda(value, args, return_type=self.rtype)
diff --git a/esphome/components/lvgl/lv_validation.py b/esphome/components/lvgl/lv_validation.py
index 9c1dd22085..947e44b131 100644
--- a/esphome/components/lvgl/lv_validation.py
+++ b/esphome/components/lvgl/lv_validation.py
@@ -1,5 +1,5 @@
 import re
-from typing import TYPE_CHECKING, Any
+from typing import Any
 
 import esphome.codegen as cg
 from esphome.components import image
@@ -404,14 +404,9 @@ class TextValidator(LValidator):
         self, value: Any, args: list[tuple[SafeExpType, str]] | None = None
     ) -> Expression:
         # Local import to avoid circular import at module level
+        from .lvcode import get_lambda_context_args
 
-        from .lvcode import CodeContext, LambdaContext
-
-        if TYPE_CHECKING:
-            # CodeContext does not have get_automation_parameters
-            # so we need to assert the type here
-            assert isinstance(CodeContext.code_context, LambdaContext)
-        args = args or CodeContext.code_context.get_automation_parameters()
+        args = args or get_lambda_context_args()
 
         if isinstance(value, dict):
             if format_str := value.get(CONF_FORMAT):
diff --git a/esphome/components/lvgl/lvcode.py b/esphome/components/lvgl/lvcode.py
index e2c70642a8..b79d1e88dd 100644
--- a/esphome/components/lvgl/lvcode.py
+++ b/esphome/components/lvgl/lvcode.py
@@ -1,4 +1,5 @@
 import abc
+from typing import TYPE_CHECKING
 
 from esphome import codegen as cg
 from esphome.config import Config
@@ -200,6 +201,21 @@ class LvContext(LambdaContext):
         return self.add(*args)
 
 
+def get_lambda_context_args() -> list[tuple[SafeExpType, str]]:
+    """Get automation parameters from the current lambda context if available.
+
+    When called from outside LVGL's context (e.g., from interval),
+    CodeContext.code_context will be None, so return empty args.
+    """
+    if CodeContext.code_context is None:
+        return []
+    if TYPE_CHECKING:
+        # CodeContext base class doesn't define get_automation_parameters(),
+        # but LambdaContext and LvContext (the concrete implementations) do.
+        assert isinstance(CodeContext.code_context, LambdaContext)
+    return CodeContext.code_context.get_automation_parameters()
+
+
 class LocalVariable(MockObj):
     """
     Create a local variable and enclose the code using it within a block.
diff --git a/esphome/components/one_wire/one_wire_bus.cpp b/esphome/components/one_wire/one_wire_bus.cpp
index c2542177cf..27b7d58a0f 100644
--- a/esphome/components/one_wire/one_wire_bus.cpp
+++ b/esphome/components/one_wire/one_wire_bus.cpp
@@ -49,7 +49,8 @@ void OneWireBus::search() {
       break;
     auto *address8 = reinterpret_cast<uint8_t *>(&address);
     if (crc8(address8, 7) != address8[7]) {
-      ESP_LOGW(TAG, "Dallas device 0x%s has invalid CRC.", format_hex(address).c_str());
+      char hex_buf[17];
+      ESP_LOGW(TAG, "Dallas device 0x%s has invalid CRC.", format_hex_to(hex_buf, address));
     } else {
       this->devices_.push_back(address);
     }
@@ -82,8 +83,9 @@ void OneWireBus::dump_devices_(const char *tag) {
     ESP_LOGW(tag, "  Found no devices!");
   } else {
     ESP_LOGCONFIG(tag, "  Found devices:");
+    char hex_buf[17];  // uint64_t = 16 hex chars + null
     for (auto &address : this->devices_) {
-      ESP_LOGCONFIG(tag, "    0x%s (%s)", format_hex(address).c_str(), LOG_STR_ARG(get_model_str(address & 0xff)));
+      ESP_LOGCONFIG(tag, "    0x%s (%s)", format_hex_to(hex_buf, address), LOG_STR_ARG(get_model_str(address & 0xff)));
     }
   }
 }
diff --git a/esphome/components/sx126x/sx126x.cpp b/esphome/components/sx126x/sx126x.cpp
index bb59f26b79..707d6f1fbf 100644
--- a/esphome/components/sx126x/sx126x.cpp
+++ b/esphome/components/sx126x/sx126x.cpp
@@ -527,7 +527,9 @@ void SX126x::dump_config() {
                   this->spreading_factor_, cr, this->preamble_size_);
   }
   if (!this->sync_value_.empty()) {
-    ESP_LOGCONFIG(TAG, "  Sync Value: 0x%s", format_hex(this->sync_value_).c_str());
+    char hex_buf[17];  // 8 bytes max = 16 hex chars + null
+    ESP_LOGCONFIG(TAG, "  Sync Value: 0x%s",
+                  format_hex_to(hex_buf, this->sync_value_.data(), this->sync_value_.size()));
   }
   if (this->is_failed()) {
     ESP_LOGE(TAG, "Configuring SX126x failed");
diff --git a/esphome/components/sx127x/sx127x.cpp b/esphome/components/sx127x/sx127x.cpp
index 8e6db5dc9e..3185574b1a 100644
--- a/esphome/components/sx127x/sx127x.cpp
+++ b/esphome/components/sx127x/sx127x.cpp
@@ -476,7 +476,9 @@ void SX127x::dump_config() {
       ESP_LOGCONFIG(TAG, "  Payload Length: %" PRIu32, this->payload_length_);
     }
     if (!this->sync_value_.empty()) {
-      ESP_LOGCONFIG(TAG, "  Sync Value: 0x%s", format_hex(this->sync_value_).c_str());
+      char hex_buf[17];  // 8 bytes max = 16 hex chars + null
+      ESP_LOGCONFIG(TAG, "  Sync Value: 0x%s",
+                    format_hex_to(hex_buf, this->sync_value_.data(), this->sync_value_.size()));
     }
     if (this->preamble_size_ > 0 || this->preamble_detect_ > 0) {
       ESP_LOGCONFIG(TAG,
diff --git a/esphome/components/wifi/wifi_component.cpp b/esphome/components/wifi/wifi_component.cpp
index fedb7ff8b3..d2b15ee982 100644
--- a/esphome/components/wifi/wifi_component.cpp
+++ b/esphome/components/wifi/wifi_component.cpp
@@ -899,12 +899,20 @@ void WiFiComponent::print_connect_params_() {
     ESP_LOGCONFIG(TAG, "  Disabled");
     return;
   }
+  // Use stack buffers for IP address formatting to avoid heap allocations
+  char ip_buf[network::IP_ADDRESS_BUFFER_SIZE];
   for (auto &ip : wifi_sta_ip_addresses()) {
     if (ip.is_set()) {
-      ESP_LOGCONFIG(TAG, "  IP Address: %s", ip.str().c_str());
+      ESP_LOGCONFIG(TAG, "  IP Address: %s", ip.str_to(ip_buf));
     }
   }
   int8_t rssi = wifi_rssi();
+  // Use stack buffers for SSID and all IP addresses to avoid heap allocations
+  char ssid_buf[SSID_BUFFER_SIZE];
+  char subnet_buf[network::IP_ADDRESS_BUFFER_SIZE];
+  char gateway_buf[network::IP_ADDRESS_BUFFER_SIZE];
+  char dns1_buf[network::IP_ADDRESS_BUFFER_SIZE];
+  char dns2_buf[network::IP_ADDRESS_BUFFER_SIZE];
   ESP_LOGCONFIG(TAG,
                 "  SSID: " LOG_SECRET("'%s'") "\n"
                                               "  BSSID: " LOG_SECRET("%s") "\n"
@@ -915,9 +923,9 @@ void WiFiComponent::print_connect_params_() {
                                                                            "  Gateway: %s\n"
                                                                            "  DNS1: %s\n"
                                                                            "  DNS2: %s",
-                wifi_ssid().c_str(), bssid_s, App.get_name().c_str(), rssi, LOG_STR_ARG(get_signal_bars(rssi)),
-                get_wifi_channel(), wifi_subnet_mask_().str().c_str(), wifi_gateway_ip_().str().c_str(),
-                wifi_dns_ip_(0).str().c_str(), wifi_dns_ip_(1).str().c_str());
+                wifi_ssid_to(ssid_buf), bssid_s, App.get_name().c_str(), rssi, LOG_STR_ARG(get_signal_bars(rssi)),
+                get_wifi_channel(), wifi_subnet_mask_().str_to(subnet_buf), wifi_gateway_ip_().str_to(gateway_buf),
+                wifi_dns_ip_(0).str_to(dns1_buf), wifi_dns_ip_(1).str_to(dns2_buf));
 #ifdef ESPHOME_LOG_HAS_VERBOSE
   if (const WiFiAP *config = this->get_selected_sta_(); config && config->has_bssid()) {
     ESP_LOGV(TAG, "  Priority: %d", this->get_sta_priority(config->get_bssid()));
diff --git a/esphome/components/wifi/wifi_component.h b/esphome/components/wifi/wifi_component.h
index 4f888292f1..ff2bfe12a4 100644
--- a/esphome/components/wifi/wifi_component.h
+++ b/esphome/components/wifi/wifi_component.h
@@ -61,6 +61,9 @@ namespace esphome::wifi {
 /// Sentinel value for RSSI when WiFi is not connected
 static constexpr int8_t WIFI_RSSI_DISCONNECTED = -127;
 
+/// Buffer size for SSID (IEEE 802.11 max 32 bytes + null terminator)
+static constexpr size_t SSID_BUFFER_SIZE = 33;
+
 struct SavedWifiSettings {
   char ssid[33];
   char password[65];
@@ -408,6 +411,9 @@ class WiFiComponent : public Component {
 
   network::IPAddresses wifi_sta_ip_addresses();
   std::string wifi_ssid();
+  /// Write SSID to buffer without heap allocation.
+  /// Returns pointer to buffer, or empty string if not connected.
+  const char *wifi_ssid_to(std::span<char, SSID_BUFFER_SIZE> buffer);
   bssid_t wifi_bssid();
 
   int8_t wifi_rssi();
diff --git a/esphome/components/wifi/wifi_component_esp8266.cpp b/esphome/components/wifi/wifi_component_esp8266.cpp
index 598ae2d5b7..1c744648bb 100644
--- a/esphome/components/wifi/wifi_component_esp8266.cpp
+++ b/esphome/components/wifi/wifi_component_esp8266.cpp
@@ -913,6 +913,18 @@ bssid_t WiFiComponent::wifi_bssid() {
   return bssid;
 }
 std::string WiFiComponent::wifi_ssid() { return WiFi.SSID().c_str(); }
+const char *WiFiComponent::wifi_ssid_to(std::span<char, SSID_BUFFER_SIZE> buffer) {
+  struct station_config conf {};
+  if (!wifi_station_get_config(&conf)) {
+    buffer[0] = '\0';
+    return buffer.data();
+  }
+  // conf.ssid is uint8[32], not null-terminated if full
+  size_t len = strnlen(reinterpret_cast<const char *>(conf.ssid), sizeof(conf.ssid));
+  memcpy(buffer.data(), conf.ssid, len);
+  buffer[len] = '\0';
+  return buffer.data();
+}
 int8_t WiFiComponent::wifi_rssi() {
   if (WiFi.status() != WL_CONNECTED)
     return WIFI_RSSI_DISCONNECTED;
diff --git a/esphome/components/wifi/wifi_component_esp_idf.cpp b/esphome/components/wifi/wifi_component_esp_idf.cpp
index 67314ae31f..b26ac3d2e2 100644
--- a/esphome/components/wifi/wifi_component_esp_idf.cpp
+++ b/esphome/components/wifi/wifi_component_esp_idf.cpp
@@ -1086,6 +1086,19 @@ std::string WiFiComponent::wifi_ssid() {
   size_t len = strnlen(ssid_s, sizeof(info.ssid));
   return {ssid_s, len};
 }
+const char *WiFiComponent::wifi_ssid_to(std::span<char, SSID_BUFFER_SIZE> buffer) {
+  wifi_ap_record_t info{};
+  esp_err_t err = esp_wifi_sta_get_ap_info(&info);
+  if (err != ESP_OK) {
+    buffer[0] = '\0';
+    return buffer.data();
+  }
+  // info.ssid is uint8[33], but only 32 bytes are SSID data
+  size_t len = strnlen(reinterpret_cast<const char *>(info.ssid), 32);
+  memcpy(buffer.data(), info.ssid, len);
+  buffer[len] = '\0';
+  return buffer.data();
+}
 int8_t WiFiComponent::wifi_rssi() {
   wifi_ap_record_t info;
   esp_err_t err = esp_wifi_sta_get_ap_info(&info);
diff --git a/esphome/components/wifi/wifi_component_libretiny.cpp b/esphome/components/wifi/wifi_component_libretiny.cpp
index 2aa6fa3484..9b8653d0db 100644
--- a/esphome/components/wifi/wifi_component_libretiny.cpp
+++ b/esphome/components/wifi/wifi_component_libretiny.cpp
@@ -554,6 +554,14 @@ bssid_t WiFiComponent::wifi_bssid() {
   return bssid;
 }
 std::string WiFiComponent::wifi_ssid() { return WiFi.SSID().c_str(); }
+const char *WiFiComponent::wifi_ssid_to(std::span<char, SSID_BUFFER_SIZE> buffer) {
+  // TODO: Find direct LibreTiny API to avoid Arduino String allocation
+  String ssid = WiFi.SSID();
+  size_t len = std::min(static_cast<size_t>(ssid.length()), SSID_BUFFER_SIZE - 1);
+  memcpy(buffer.data(), ssid.c_str(), len);
+  buffer[len] = '\0';
+  return buffer.data();
+}
 int8_t WiFiComponent::wifi_rssi() { return WiFi.status() == WL_CONNECTED ? WiFi.RSSI() : WIFI_RSSI_DISCONNECTED; }
 int32_t WiFiComponent::get_wifi_channel() { return WiFi.channel(); }
 network::IPAddress WiFiComponent::wifi_subnet_mask_() { return {WiFi.subnetMask()}; }
diff --git a/esphome/components/wifi/wifi_component_pico_w.cpp b/esphome/components/wifi/wifi_component_pico_w.cpp
index b755b8544f..1aa737ff4a 100644
--- a/esphome/components/wifi/wifi_component_pico_w.cpp
+++ b/esphome/components/wifi/wifi_component_pico_w.cpp
@@ -214,6 +214,14 @@ bssid_t WiFiComponent::wifi_bssid() {
   return bssid;
 }
 std::string WiFiComponent::wifi_ssid() { return WiFi.SSID().c_str(); }
+const char *WiFiComponent::wifi_ssid_to(std::span<char, SSID_BUFFER_SIZE> buffer) {
+  // TODO: Find direct CYW43 API to avoid Arduino String allocation
+  String ssid = WiFi.SSID();
+  size_t len = std::min(static_cast<size_t>(ssid.length()), SSID_BUFFER_SIZE - 1);
+  memcpy(buffer.data(), ssid.c_str(), len);
+  buffer[len] = '\0';
+  return buffer.data();
+}
 int8_t WiFiComponent::wifi_rssi() { return WiFi.status() == WL_CONNECTED ? WiFi.RSSI() : WIFI_RSSI_DISCONNECTED; }
 int32_t WiFiComponent::get_wifi_channel() { return WiFi.channel(); }
 
diff --git a/esphome/core/helpers.cpp b/esphome/core/helpers.cpp
index f45e21d5ca..68f8431d2d 100644
--- a/esphome/core/helpers.cpp
+++ b/esphome/core/helpers.cpp
@@ -297,6 +297,19 @@ std::string format_hex(const uint8_t *data, size_t length) {
 }
 std::string format_hex(const std::vector<uint8_t> &data) { return format_hex(data.data(), data.size()); }
 
+char *format_hex_to(char *buffer, size_t buffer_size, const uint8_t *data, size_t length) {
+  size_t max_bytes = (buffer_size - 1) / 2;
+  if (length > max_bytes) {
+    length = max_bytes;
+  }
+  for (size_t i = 0; i < length; i++) {
+    buffer[2 * i] = format_hex_char(data[i] >> 4);
+    buffer[2 * i + 1] = format_hex_char(data[i] & 0x0F);
+  }
+  buffer[length * 2] = '\0';
+  return buffer;
+}
+
 // Shared implementation for uint8_t and string hex formatting
 static std::string format_hex_pretty_uint8(const uint8_t *data, size_t length, char separator, bool show_length) {
   if (data == nullptr || length == 0)
diff --git a/esphome/core/helpers.h b/esphome/core/helpers.h
index d849ffd29a..6221a57978 100644
--- a/esphome/core/helpers.h
+++ b/esphome/core/helpers.h
@@ -747,6 +747,24 @@ inline void format_mac_addr_lower_no_sep(const uint8_t *mac, char *output) {
   output[12] = '\0';
 }
 
+/// Format byte array as lowercase hex to buffer (base implementation).
+char *format_hex_to(char *buffer, size_t buffer_size, const uint8_t *data, size_t length);
+
+/// Format byte array as lowercase hex to buffer. Automatically deduces buffer size.
+/// Truncates output if data exceeds buffer capacity. Returns pointer to buffer.
+template<size_t N> inline char *format_hex_to(char (&buffer)[N], const uint8_t *data, size_t length) {
+  static_assert(N >= 3, "Buffer must hold at least one hex byte (3 chars)");
+  return format_hex_to(buffer, N, data, length);
+}
+
+/// Format an unsigned integer in lowercased hex to buffer, starting with the most significant byte.
+template<size_t N, typename T, enable_if_t<std::is_unsigned<T>::value, int> = 0>
+inline char *format_hex_to(char (&buffer)[N], T val) {
+  static_assert(N >= sizeof(T) * 2 + 1, "Buffer too small for type");
+  val = convert_big_endian(val);
+  return format_hex_to(buffer, reinterpret_cast<const uint8_t *>(&val), sizeof(T));
+}
+
 /// Format the six-byte array \p mac into a MAC address.
 std::string format_mac_address_pretty(const uint8_t mac[6]);
 /// Format the byte array \p data of length \p len in lowercased hex.