diff --git a/homeassistant/components/config/entity_registry.py b/homeassistant/components/config/entity_registry.py
index 43196acf319..1040a500f3c 100644
--- a/homeassistant/components/config/entity_registry.py
+++ b/homeassistant/components/config/entity_registry.py
@@ -177,6 +177,7 @@ def _entry_dict(entry):
         "name": entry.name,
         "icon": entry.icon,
         "platform": entry.platform,
+        "entity_category": entry.entity_category,
     }
 
 
diff --git a/homeassistant/const.py b/homeassistant/const.py
index 483109737ed..f4387c9bbce 100644
--- a/homeassistant/const.py
+++ b/homeassistant/const.py
@@ -704,3 +704,6 @@ CLOUD_NEVER_EXPOSED_ENTITIES: Final[list[str]] = ["group.all_locks"]
 
 # The ID of the Home Assistant Cast App
 CAST_APP_ID_HOMEASSISTANT: Final = "B12CE3CA"
+
+ENTITY_CATEGORY_CONFIG: Final = "config"
+ENTITY_CATEGORY_DIAGNOSTIC: Final = "diagnostic"
diff --git a/homeassistant/helpers/entity.py b/homeassistant/helpers/entity.py
index 1d3b331b8ab..584fa4f0554 100644
--- a/homeassistant/helpers/entity.py
+++ b/homeassistant/helpers/entity.py
@@ -11,7 +11,7 @@ import logging
 import math
 import sys
 from timeit import default_timer as timer
-from typing import Any, TypedDict, final
+from typing import Any, Literal, TypedDict, final
 
 from homeassistant.config import DATA_CUSTOMIZE
 from homeassistant.const import (
@@ -180,6 +180,7 @@ class EntityDescription:
     key: str
 
     device_class: str | None = None
+    entity_category: Literal["config", "diagnostic"] | None = None
     entity_registry_enabled_default: bool = True
     force_update: bool = False
     icon: str | None = None
@@ -238,6 +239,7 @@ class Entity(ABC):
     _attr_context_recent_time: timedelta = timedelta(seconds=5)
     _attr_device_class: str | None
     _attr_device_info: DeviceInfo | None = None
+    _attr_entity_category: str | None
     _attr_entity_picture: str | None = None
     _attr_entity_registry_enabled_default: bool
     _attr_extra_state_attributes: MutableMapping[str, Any]
@@ -404,6 +406,15 @@ class Entity(ABC):
         """Return the attribution."""
         return self._attr_attribution
 
+    @property
+    def entity_category(self) -> str | None:
+        """Return the category of the entity, if any."""
+        if hasattr(self, "_attr_entity_category"):
+            return self._attr_entity_category
+        if hasattr(self, "entity_description"):
+            return self.entity_description.entity_category
+        return None
+
     # DO NOT OVERWRITE
     # These properties and methods are either managed by Home Assistant or they
     # are used to perform a very specific function. Overwriting these may
diff --git a/homeassistant/helpers/entity_platform.py b/homeassistant/helpers/entity_platform.py
index 831f6c9a4b6..5fb095c4f02 100644
--- a/homeassistant/helpers/entity_platform.py
+++ b/homeassistant/helpers/entity_platform.py
@@ -501,6 +501,7 @@ class EntityPlatform:
                 unit_of_measurement=entity.unit_of_measurement,
                 original_name=entity.name,
                 original_icon=entity.icon,
+                entity_category=entity.entity_category,
             )
 
             entity.registry_entry = entry
diff --git a/homeassistant/helpers/entity_registry.py b/homeassistant/helpers/entity_registry.py
index 88233b30df7..bedbdc51785 100644
--- a/homeassistant/helpers/entity_registry.py
+++ b/homeassistant/helpers/entity_registry.py
@@ -106,6 +106,7 @@ class RegistryEntry:
     # As set by integration
     original_name: str | None = attr.ib(default=None)
     original_icon: str | None = attr.ib(default=None)
+    entity_category: str | None = attr.ib(default=None)
     domain: str = attr.ib(init=False, repr=False)
 
     @domain.default
@@ -256,6 +257,7 @@ class EntityRegistry:
         unit_of_measurement: str | None = None,
         original_name: str | None = None,
         original_icon: str | None = None,
+        entity_category: str | None = None,
     ) -> RegistryEntry:
         """Get entity. Create if it doesn't exist."""
         config_entry_id = None
@@ -276,6 +278,7 @@ class EntityRegistry:
                 unit_of_measurement=unit_of_measurement or UNDEFINED,
                 original_name=original_name or UNDEFINED,
                 original_icon=original_icon or UNDEFINED,
+                entity_category=entity_category or UNDEFINED,
                 # When we changed our slugify algorithm, we invalidated some
                 # stored entity IDs with either a __ or ending in _.
                 # Fix introduced in 0.86 (Jan 23, 2019). Next line can be
@@ -310,6 +313,7 @@ class EntityRegistry:
             unit_of_measurement=unit_of_measurement,
             original_name=original_name,
             original_icon=original_icon,
+            entity_category=entity_category,
         )
         self._register_entry(entity)
         _LOGGER.info("Registered new %s.%s entity: %s", domain, platform, entity_id)
@@ -418,6 +422,7 @@ class EntityRegistry:
         unit_of_measurement: str | None | UndefinedType = UNDEFINED,
         original_name: str | None | UndefinedType = UNDEFINED,
         original_icon: str | None | UndefinedType = UNDEFINED,
+        entity_category: str | None | UndefinedType = UNDEFINED,
     ) -> RegistryEntry:
         """Private facing update properties method."""
         old = self.entities[entity_id]
@@ -438,6 +443,7 @@ class EntityRegistry:
             ("unit_of_measurement", unit_of_measurement),
             ("original_name", original_name),
             ("original_icon", original_icon),
+            ("entity_category", entity_category),
         ):
             if value is not UNDEFINED and value != getattr(old, attr_name):
                 new_values[attr_name] = value
@@ -523,6 +529,7 @@ class EntityRegistry:
                     unit_of_measurement=entity.get("unit_of_measurement"),
                     original_name=entity.get("original_name"),
                     original_icon=entity.get("original_icon"),
+                    entity_category=entity.get("entity_category"),
                 )
 
         self.entities = entities
@@ -555,6 +562,7 @@ class EntityRegistry:
                 "unit_of_measurement": entry.unit_of_measurement,
                 "original_name": entry.original_name,
                 "original_icon": entry.original_icon,
+                "entity_category": entry.entity_category,
             }
             for entry in self.entities.values()
         ]
diff --git a/tests/components/config/test_entity_registry.py b/tests/components/config/test_entity_registry.py
index 3d5861c2db3..3faff1222d4 100644
--- a/tests/components/config/test_entity_registry.py
+++ b/tests/components/config/test_entity_registry.py
@@ -1,6 +1,4 @@
 """Test entity_registry API."""
-from collections import OrderedDict
-
 import pytest
 
 from homeassistant.components.config import entity_registry
@@ -31,18 +29,22 @@ def device_registry(hass):
 
 async def test_list_entities(hass, client):
     """Test list entries."""
-    entities = OrderedDict()
-    entities["test_domain.name"] = RegistryEntry(
-        entity_id="test_domain.name",
-        unique_id="1234",
-        platform="test_platform",
-        name="Hello World",
+    mock_registry(
+        hass,
+        {
+            "test_domain.name": RegistryEntry(
+                entity_id="test_domain.name",
+                unique_id="1234",
+                platform="test_platform",
+                name="Hello World",
+            ),
+            "test_domain.no_name": RegistryEntry(
+                entity_id="test_domain.no_name",
+                unique_id="6789",
+                platform="test_platform",
+            ),
+        },
     )
-    entities["test_domain.no_name"] = RegistryEntry(
-        entity_id="test_domain.no_name", unique_id="6789", platform="test_platform"
-    )
-
-    mock_registry(hass, entities)
 
     await client.send_json({"id": 5, "type": "config/entity_registry/list"})
     msg = await client.receive_json()
@@ -57,6 +59,7 @@ async def test_list_entities(hass, client):
             "name": "Hello World",
             "icon": None,
             "platform": "test_platform",
+            "entity_category": None,
         },
         {
             "config_entry_id": None,
@@ -67,6 +70,7 @@ async def test_list_entities(hass, client):
             "name": None,
             "icon": None,
             "platform": "test_platform",
+            "entity_category": None,
         },
     ]
 
@@ -108,6 +112,7 @@ async def test_get_entity(hass, client):
         "original_icon": None,
         "capabilities": None,
         "unique_id": "1234",
+        "entity_category": None,
     }
 
     await client.send_json(
@@ -132,6 +137,7 @@ async def test_get_entity(hass, client):
         "original_icon": None,
         "capabilities": None,
         "unique_id": "6789",
+        "entity_category": None,
     }
 
 
@@ -187,6 +193,7 @@ async def test_update_entity(hass, client):
             "original_icon": None,
             "capabilities": None,
             "unique_id": "1234",
+            "entity_category": None,
         }
     }
 
@@ -235,6 +242,7 @@ async def test_update_entity(hass, client):
             "original_icon": None,
             "capabilities": None,
             "unique_id": "1234",
+            "entity_category": None,
         },
         "reload_delay": 30,
     }
@@ -289,6 +297,7 @@ async def test_update_entity_require_restart(hass, client):
             "original_icon": None,
             "capabilities": None,
             "unique_id": "1234",
+            "entity_category": None,
         },
         "require_restart": True,
     }
@@ -390,6 +399,7 @@ async def test_update_entity_no_changes(hass, client):
             "original_icon": None,
             "capabilities": None,
             "unique_id": "1234",
+            "entity_category": None,
         }
     }
 
@@ -470,6 +480,7 @@ async def test_update_entity_id(hass, client):
             "original_icon": None,
             "capabilities": None,
             "unique_id": "1234",
+            "entity_category": None,
         }
     }
 
diff --git a/tests/helpers/test_entity.py b/tests/helpers/test_entity.py
index bdb7a2782a3..e334e6d2c56 100644
--- a/tests/helpers/test_entity.py
+++ b/tests/helpers/test_entity.py
@@ -809,3 +809,23 @@ async def test_attribution_attribute(hass):
 
     state = hass.states.get(mock_entity.entity_id)
     assert state.attributes.get(ATTR_ATTRIBUTION) == "Home Assistant"
+
+
+async def test_entity_category_property(hass):
+    """Test entity category property."""
+    mock_entity1 = entity.Entity()
+    mock_entity1.hass = hass
+    mock_entity1.entity_description = entity.EntityDescription(
+        key="abc", entity_category="ignore_me"
+    )
+    mock_entity1.entity_id = "hello.world"
+    mock_entity1._attr_entity_category = "config"
+    assert mock_entity1.entity_category == "config"
+
+    mock_entity2 = entity.Entity()
+    mock_entity2.hass = hass
+    mock_entity2.entity_description = entity.EntityDescription(
+        key="abc", entity_category="config"
+    )
+    mock_entity2.entity_id = "hello.world"
+    assert mock_entity2.entity_category == "config"