diff --git a/homeassistant/helpers/entity.py b/homeassistant/helpers/entity.py
index 3d22e2538a3..e87eb15b954 100644
--- a/homeassistant/helpers/entity.py
+++ b/homeassistant/helpers/entity.py
@@ -772,9 +772,10 @@ class Entity(ABC):
         ):
             return name
 
+        device_name = device_entry.name_by_user or device_entry.name
         if self.use_device_name:
-            return device_entry.name_by_user or device_entry.name
-        return f"{device_entry.name_by_user or device_entry.name} {name}"
+            return device_name
+        return f"{device_name} {name}" if device_name else name
 
     @callback
     def _async_write_ha_state(self) -> None:
diff --git a/tests/helpers/test_entity.py b/tests/helpers/test_entity.py
index 85a7932aef8..7de6f70e793 100644
--- a/tests/helpers/test_entity.py
+++ b/tests/helpers/test_entity.py
@@ -20,7 +20,7 @@ from homeassistant.const import (
 from homeassistant.core import Context, HomeAssistant, HomeAssistantError
 from homeassistant.helpers import device_registry as dr, entity, entity_registry as er
 from homeassistant.helpers.entity_component import async_update_entity
-from homeassistant.helpers.typing import UNDEFINED
+from homeassistant.helpers.typing import UNDEFINED, UndefinedType
 
 from tests.common import (
     MockConfigEntry,
@@ -989,12 +989,20 @@ async def _test_friendly_name(
 
 
 @pytest.mark.parametrize(
-    ("has_entity_name", "entity_name", "expected_friendly_name", "warn_implicit_name"),
     (
-        (False, "Entity Blu", "Entity Blu", False),
-        (False, None, None, False),
-        (True, "Entity Blu", "Device Bla Entity Blu", False),
-        (True, None, "Device Bla", False),
+        "has_entity_name",
+        "entity_name",
+        "device_name",
+        "expected_friendly_name",
+        "warn_implicit_name",
+    ),
+    (
+        (False, "Entity Blu", "Device Bla", "Entity Blu", False),
+        (False, None, "Device Bla", None, False),
+        (True, "Entity Blu", "Device Bla", "Device Bla Entity Blu", False),
+        (True, None, "Device Bla", "Device Bla", False),
+        (True, "Entity Blu", UNDEFINED, "Entity Blu", False),
+        (True, "Entity Blu", None, "Mock Title Entity Blu", False),
     ),
 )
 async def test_friendly_name_attr(
@@ -1002,6 +1010,7 @@ async def test_friendly_name_attr(
     caplog: pytest.LogCaptureFixture,
     has_entity_name: bool,
     entity_name: str | None,
+    device_name: str | None | UndefinedType,
     expected_friendly_name: str | None,
     warn_implicit_name: bool,
 ) -> None:
@@ -1012,7 +1021,7 @@ async def test_friendly_name_attr(
         device_info={
             "identifiers": {("hue", "1234")},
             "connections": {(dr.CONNECTION_NETWORK_MAC, "abcd")},
-            "name": "Device Bla",
+            "name": device_name,
         },
     )
     ent._attr_has_entity_name = has_entity_name