diff --git a/esphome/core/entity_base.cpp b/esphome/core/entity_base.cpp
index e5231ed759..725a8569a3 100644
--- a/esphome/core/entity_base.cpp
+++ b/esphome/core/entity_base.cpp
@@ -35,15 +35,6 @@ std::string EntityBase::get_icon() const {
 }
 void EntityBase::set_icon(const char *icon) { this->icon_c_str_ = icon; }
 
-// Entity Device id
-const StringRef &EntityBase::get_device_id() const {
-  if (this->device_id_.empty()) {
-    return StringRef("");
-  }
-  return this->device_id_;
-}
-void EntityBase::set_device_id(const std::string device_id) { this->device_id_ = StringRef(device_id); }
-
 // Entity Category
 EntityCategory EntityBase::get_entity_category() const { return this->entity_category_; }
 void EntityBase::set_entity_category(EntityCategory entity_category) { this->entity_category_ = entity_category; }
diff --git a/esphome/core/entity_base.h b/esphome/core/entity_base.h
index e52406c425..e66fbb66e6 100644
--- a/esphome/core/entity_base.h
+++ b/esphome/core/entity_base.h
@@ -48,8 +48,8 @@ class EntityBase {
   void set_icon(const char *icon);
 
   // Get/set this entity's device id
-  const StringRef &get_device_id() const;
-  void set_device_id(const std::string device_id);
+  const StringRef &get_device_id() const { return this->device_id_; }
+  void set_device_id(const std::string &device_id) { this->device_id_ = StringRef(device_id); }
 
  protected:
   /// The hash_base() function has been deprecated. It is kept in this
@@ -65,7 +65,7 @@ class EntityBase {
   bool internal_{false};
   bool disabled_by_default_{false};
   EntityCategory entity_category_{ENTITY_CATEGORY_NONE};
-  StringRef device_id_;
+  StringRef device_id_{""};
 };
 
 class EntityBase_DeviceClass {  // NOLINT(readability-identifier-naming)