diff --git a/esphome/components/tsl2561/tsl2561.cpp b/esphome/components/tsl2561/tsl2561.cpp
index 5c53ed607ff..4e4d403488d 100644
--- a/esphome/components/tsl2561/tsl2561.cpp
+++ b/esphome/components/tsl2561/tsl2561.cpp
@@ -145,7 +145,6 @@ float TSL2561Sensor::get_integration_time_ms_() {
 void TSL2561Sensor::set_integration_time(TSL2561IntegrationTime integration_time) {
   this->integration_time_ = integration_time;
 }
-void TSL2561Sensor::set_gain(TSL2561Gain gain) { this->gain_ = gain; }
 
 bool TSL2561Sensor::tsl2561_write_byte(uint8_t a_register, uint8_t value) {
   return this->write_byte(a_register | TSL2561_COMMAND_BIT, value);
diff --git a/esphome/components/tsl2561/tsl2561.h b/esphome/components/tsl2561/tsl2561.h
index 8f6251c1342..0800b87c461 100644
--- a/esphome/components/tsl2561/tsl2561.h
+++ b/esphome/components/tsl2561/tsl2561.h
@@ -51,7 +51,7 @@ class TSL2561Sensor final : public sensor::Sensor, public PollingComponent, publ
    *
    * @param gain The new gain.
    */
-  void set_gain(TSL2561Gain gain);
+  void set_gain(TSL2561Gain gain) { this->gain_ = gain; }
 
   /** The "CS" package of this sensor has a slightly different formula for
    * converting the raw values. Use this setting to indicate that this is a CS
diff --git a/esphome/components/tsl2591/tsl2591.cpp b/esphome/components/tsl2591/tsl2591.cpp
index a741b087971..d147aae88ab 100644
--- a/esphome/components/tsl2591/tsl2591.cpp
+++ b/esphome/components/tsl2591/tsl2591.cpp
@@ -216,8 +216,6 @@ void TSL2591Component::set_integration_time(TSL2591IntegrationTime integration_t
   this->integration_time_ = integration_time;
 }
 
-void TSL2591Component::set_gain(TSL2591ComponentGain gain) { this->component_gain_ = gain; }
-
 void TSL2591Component::set_device_and_glass_attenuation_factors(float device_factor, float glass_attenuation_factor) {
   this->device_factor_ = device_factor;
   this->glass_attenuation_factor_ = glass_attenuation_factor;
diff --git a/esphome/components/tsl2591/tsl2591.h b/esphome/components/tsl2591/tsl2591.h
index 1e699329eb3..c65fc5f6e54 100644
--- a/esphome/components/tsl2591/tsl2591.h
+++ b/esphome/components/tsl2591/tsl2591.h
@@ -241,7 +241,7 @@ class TSL2591Component final : public PollingComponent, public i2c::I2CDevice {
   /** Used by ESPHome framework. Does NOT actually set the value on the device. */
   void set_integration_time(TSL2591IntegrationTime integration_time);
   /** Used by ESPHome framework. Does NOT actually set the value on the device. */
-  void set_gain(TSL2591ComponentGain gain);
+  void set_gain(TSL2591ComponentGain gain) { this->component_gain_ = gain; }
   /** Used by ESPHome framework. */
   void setup() override;
   /** Used by ESPHome framework. */