diff --git a/esphome/components/light/light_state.cpp b/esphome/components/light/light_state.cpp
index 50ebd8882b..fe6538e65e 100644
--- a/esphome/components/light/light_state.cpp
+++ b/esphome/components/light/light_state.cpp
@@ -120,6 +120,7 @@ void LightState::loop() {
   // Apply transformer (if any)
   if (this->transformer_ != nullptr) {
     auto values = this->transformer_->apply();
+    this->is_transformer_active_ = true;
     if (values.has_value()) {
       this->current_values = *values;
       this->output_->update_state(this);
@@ -131,6 +132,7 @@ void LightState::loop() {
       this->current_values = this->transformer_->get_target_values();
 
       this->transformer_->stop();
+      this->is_transformer_active_ = false;
       this->transformer_ = nullptr;
       this->target_state_reached_callback_.call();
     }
@@ -214,6 +216,8 @@ void LightState::current_values_as_ct(float *color_temperature, float *white_bri
                              this->gamma_correct_);
 }
 
+bool LightState::is_transformer_active() { return this->is_transformer_active_; }
+
 void LightState::start_effect_(uint32_t effect_index) {
   this->stop_effect_();
   if (effect_index == 0)
@@ -263,6 +267,7 @@ void LightState::start_flash_(const LightColorValues &target, uint32_t length, b
 }
 
 void LightState::set_immediately_(const LightColorValues &target, bool set_remote_values) {
+  this->is_transformer_active_ = false;
   this->transformer_ = nullptr;
   this->current_values = target;
   if (set_remote_values) {
diff --git a/esphome/components/light/light_state.h b/esphome/components/light/light_state.h
index ac4718ade5..b0aaa453b5 100644
--- a/esphome/components/light/light_state.h
+++ b/esphome/components/light/light_state.h
@@ -144,6 +144,17 @@ class LightState : public EntityBase, public Component {
 
   void current_values_as_ct(float *color_temperature, float *white_brightness);
 
+  /**
+   * Indicator if a transformer (e.g. transition) is active. This is useful
+   * for effects e.g. at the start of the apply() method, add a check like:
+   *
+   * if (this->state_->is_transformer_active()) {
+   *   // Something is already running.
+   *   return;
+   * }
+   */
+  bool is_transformer_active();
+
  protected:
   friend LightOutput;
   friend LightCall;
@@ -203,6 +214,9 @@ class LightState : public EntityBase, public Component {
   LightRestoreMode restore_mode_;
   /// List of effects for this light.
   std::vector<LightEffect *> effects_;
+
+  // for effects, true if a transformer (transition) is active.
+  bool is_transformer_active_ = false;
 };
 
 }  // namespace light