diff --git a/esphome/components/template/binary_sensor/template_binary_sensor.h b/esphome/components/template/binary_sensor/template_binary_sensor.h
index f63738d93f..0373f898a8 100644
--- a/esphome/components/template/binary_sensor/template_binary_sensor.h
+++ b/esphome/components/template/binary_sensor/template_binary_sensor.h
@@ -1,7 +1,7 @@
 #pragma once
 
 #include "esphome/core/component.h"
-#include "../template_lambda.h"
+#include "esphome/core/template_lambda.h"
 #include "esphome/components/binary_sensor/binary_sensor.h"
 
 namespace esphome {
diff --git a/esphome/components/template/cover/template_cover.h b/esphome/components/template/cover/template_cover.h
index 57a5e11c5c..56ab61c3fb 100644
--- a/esphome/components/template/cover/template_cover.h
+++ b/esphome/components/template/cover/template_cover.h
@@ -2,7 +2,7 @@
 
 #include "esphome/core/component.h"
 #include "esphome/core/automation.h"
-#include "../template_lambda.h"
+#include "esphome/core/template_lambda.h"
 #include "esphome/components/cover/cover.h"
 
 namespace esphome {
diff --git a/esphome/components/template/datetime/template_date.h b/esphome/components/template/datetime/template_date.h
index b0fdbcbfbb..7fed704d0e 100644
--- a/esphome/components/template/datetime/template_date.h
+++ b/esphome/components/template/datetime/template_date.h
@@ -9,7 +9,7 @@
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
 #include "esphome/core/time.h"
-#include "../template_lambda.h"
+#include "esphome/core/template_lambda.h"
 
 namespace esphome {
 namespace template_ {
diff --git a/esphome/components/template/datetime/template_datetime.h b/esphome/components/template/datetime/template_datetime.h
index b1c94d7d34..ec45bf0326 100644
--- a/esphome/components/template/datetime/template_datetime.h
+++ b/esphome/components/template/datetime/template_datetime.h
@@ -9,7 +9,7 @@
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
 #include "esphome/core/time.h"
-#include "../template_lambda.h"
+#include "esphome/core/template_lambda.h"
 
 namespace esphome {
 namespace template_ {
diff --git a/esphome/components/template/datetime/template_time.h b/esphome/components/template/datetime/template_time.h
index c6938fe7a0..ea7474c0ba 100644
--- a/esphome/components/template/datetime/template_time.h
+++ b/esphome/components/template/datetime/template_time.h
@@ -9,7 +9,7 @@
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
 #include "esphome/core/time.h"
-#include "../template_lambda.h"
+#include "esphome/core/template_lambda.h"
 
 namespace esphome {
 namespace template_ {
diff --git a/esphome/components/template/lock/template_lock.h b/esphome/components/template/lock/template_lock.h
index 2bb11bfef6..347c4effb3 100644
--- a/esphome/components/template/lock/template_lock.h
+++ b/esphome/components/template/lock/template_lock.h
@@ -2,7 +2,7 @@
 
 #include "esphome/core/component.h"
 #include "esphome/core/automation.h"
-#include "../template_lambda.h"
+#include "esphome/core/template_lambda.h"
 #include "esphome/components/lock/lock.h"
 
 namespace esphome {
diff --git a/esphome/components/template/number/template_number.h b/esphome/components/template/number/template_number.h
index 1a6e9d964f..a9307e9246 100644
--- a/esphome/components/template/number/template_number.h
+++ b/esphome/components/template/number/template_number.h
@@ -4,7 +4,7 @@
 #include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
-#include "../template_lambda.h"
+#include "esphome/core/template_lambda.h"
 
 namespace esphome {
 namespace template_ {
diff --git a/esphome/components/template/select/template_select.h b/esphome/components/template/select/template_select.h
index 53cadfa303..1c33153872 100644
--- a/esphome/components/template/select/template_select.h
+++ b/esphome/components/template/select/template_select.h
@@ -4,7 +4,7 @@
 #include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
-#include "../template_lambda.h"
+#include "esphome/core/template_lambda.h"
 
 namespace esphome {
 namespace template_ {
diff --git a/esphome/components/template/sensor/template_sensor.h b/esphome/components/template/sensor/template_sensor.h
index 27980414f9..793d754a0f 100644
--- a/esphome/components/template/sensor/template_sensor.h
+++ b/esphome/components/template/sensor/template_sensor.h
@@ -1,7 +1,7 @@
 #pragma once
 
 #include "esphome/core/component.h"
-#include "../template_lambda.h"
+#include "esphome/core/template_lambda.h"
 #include "esphome/components/sensor/sensor.h"
 
 namespace esphome {
diff --git a/esphome/components/template/switch/template_switch.h b/esphome/components/template/switch/template_switch.h
index f436f657ae..47154fd047 100644
--- a/esphome/components/template/switch/template_switch.h
+++ b/esphome/components/template/switch/template_switch.h
@@ -2,7 +2,7 @@
 
 #include "esphome/core/component.h"
 #include "esphome/core/automation.h"
-#include "../template_lambda.h"
+#include "esphome/core/template_lambda.h"
 #include "esphome/components/switch/switch.h"
 
 namespace esphome {
diff --git a/esphome/components/template/template_lambda.h b/esphome/components/template/template_lambda.h
deleted file mode 100644
index 894b5edffa..0000000000
--- a/esphome/components/template/template_lambda.h
+++ /dev/null
@@ -1,51 +0,0 @@
-#pragma once
-
-#include "esphome/core/optional.h"
-
-namespace esphome {
-
-/** Lightweight wrapper for template platform lambdas (stateless function pointers only).
- *
- * This optimizes template platforms by storing only a function pointer (4 bytes on ESP32)
- * instead of std::function (16-32 bytes).
- *
- * IMPORTANT: This only supports stateless lambdas (no captures). The set_template() method
- * is an internal API used by YAML codegen, not intended for external use.
- *
- * Lambdas must return optional<T> to support the pattern:
- *   return {};    // Don't publish a value
- *   return 42.0;  // Publish this value
- *
- * operator() returns optional<T>, returning nullopt when no lambda is set (nullptr check).
- *
- * @tparam T The return type (e.g., float for sensor values)
- * @tparam Args Optional arguments for the lambda
- */
-template<typename T, typename... Args> class TemplateLambda {
- public:
-  TemplateLambda() : f_(nullptr) {}
-
-  /** Set the lambda function pointer.
-   * INTERNAL API: Only for use by YAML codegen.
-   * Only stateless lambdas (no captures) are supported.
-   */
-  void set(optional<T> (*f)(Args...)) { this->f_ = f; }
-
-  /** Check if a lambda is set */
-  bool has_value() const { return this->f_ != nullptr; }
-
-  /** Call the lambda, returning nullopt if no lambda is set */
-  optional<T> operator()(Args... args) {
-    if (this->f_ == nullptr)
-      return nullopt;
-    return this->f_(args...);
-  }
-
-  /** Alias for operator() for compatibility */
-  optional<T> call(Args... args) { return (*this)(args...); }
-
- protected:
-  optional<T> (*f_)(Args...);  // Function pointer (4 bytes on ESP32)
-};
-
-}  // namespace esphome
diff --git a/esphome/components/template/text/template_text.h b/esphome/components/template/text/template_text.h
index fd28800bab..c12021f80e 100644
--- a/esphome/components/template/text/template_text.h
+++ b/esphome/components/template/text/template_text.h
@@ -4,7 +4,7 @@
 #include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
-#include "../template_lambda.h"
+#include "esphome/core/template_lambda.h"
 
 namespace esphome {
 namespace template_ {
diff --git a/esphome/components/template/text_sensor/template_text_sensor.h b/esphome/components/template/text_sensor/template_text_sensor.h
index fda28f53c7..0d01c72023 100644
--- a/esphome/components/template/text_sensor/template_text_sensor.h
+++ b/esphome/components/template/text_sensor/template_text_sensor.h
@@ -2,7 +2,7 @@
 
 #include "esphome/core/component.h"
 #include "esphome/core/automation.h"
-#include "../template_lambda.h"
+#include "esphome/core/template_lambda.h"
 #include "esphome/components/text_sensor/text_sensor.h"
 
 namespace esphome {
diff --git a/esphome/components/template/valve/template_valve.h b/esphome/components/template/valve/template_valve.h
index 7713091673..23a77ff918 100644
--- a/esphome/components/template/valve/template_valve.h
+++ b/esphome/components/template/valve/template_valve.h
@@ -2,7 +2,7 @@
 
 #include "esphome/core/component.h"
 #include "esphome/core/automation.h"
-#include "../template_lambda.h"
+#include "esphome/core/template_lambda.h"
 #include "esphome/components/valve/valve.h"
 
 namespace esphome {
diff --git a/tests/components/template/common-base.yaml b/tests/components/template/common-base.yaml
index da449111a2..f101eea942 100644
--- a/tests/components/template/common-base.yaml
+++ b/tests/components/template/common-base.yaml
@@ -10,7 +10,7 @@ esphome:
         state: !lambda "return 42.0;"
 
     # Test C++ API: set_template() with stateless lambda (no captures)
-    # IMPORTANT: set_template() is an internal API. Only stateless lambdas are supported.
+    # NOTE: set_template() is not intended to be a public API, but we test it to ensure it doesn't break.
     - lambda: |-
         id(template_sens).set_template([]() -> esphome::optional<float> {
           return 123.0f;