diff --git a/homeassistant/helpers/entity.py b/homeassistant/helpers/entity.py
index b670c734b47..e9038d1f658 100644
--- a/homeassistant/helpers/entity.py
+++ b/homeassistant/helpers/entity.py
@@ -223,7 +223,10 @@ def convert_to_entity_category(
                 "EntityCategory instead" % (type(value).__name__, value),
                 error_if_core=False,
             )
-        return EntityCategory(value)
+        try:
+            return EntityCategory(value)
+        except ValueError:
+            return None
     return value
 
 
diff --git a/tests/helpers/test_entity_registry.py b/tests/helpers/test_entity_registry.py
index f299177a08e..1eaac0e72bf 100644
--- a/tests/helpers/test_entity_registry.py
+++ b/tests/helpers/test_entity_registry.py
@@ -1124,3 +1124,15 @@ async def test_deprecated_disabled_by_str(hass, registry, caplog):
 
     assert entry.disabled_by is er.RegistryEntryDisabler.USER
     assert " str for entity registry disabled_by. This is deprecated " in caplog.text
+
+
+async def test_invalid_entity_category_str(hass, registry, caplog):
+    """Test use of invalid entity category."""
+    entry = er.RegistryEntry(
+        "light",
+        "hue",
+        "5678",
+        entity_category="invalid",
+    )
+
+    assert entry.entity_category is None