diff --git a/homeassistant/components/google_assistant/http.py b/homeassistant/components/google_assistant/http.py
index 61768ff2be8..d5489aad05a 100644
--- a/homeassistant/components/google_assistant/http.py
+++ b/homeassistant/components/google_assistant/http.py
@@ -12,9 +12,12 @@ import jwt
 from homeassistant.components.http import HomeAssistantView
 from homeassistant.const import (
     CLOUD_NEVER_EXPOSED_ENTITIES,
+    ENTITY_CATEGORY_CONFIG,
+    ENTITY_CATEGORY_DIAGNOSTIC,
     HTTP_INTERNAL_SERVER_ERROR,
     HTTP_UNAUTHORIZED,
 )
+from homeassistant.helpers import entity_registry as er
 from homeassistant.helpers.aiohttp_client import async_get_clientsession
 from homeassistant.util import dt as dt_util
 
@@ -112,16 +115,30 @@ class GoogleConfig(AbstractConfig):
         if state.entity_id in CLOUD_NEVER_EXPOSED_ENTITIES:
             return False
 
+        entity_registry = er.async_get(self.hass)
+        registry_entry = entity_registry.async_get(state.entity_id)
+        if registry_entry:
+            auxiliary_entity = registry_entry.entity_category in (
+                ENTITY_CATEGORY_CONFIG,
+                ENTITY_CATEGORY_DIAGNOSTIC,
+            )
+        else:
+            auxiliary_entity = False
+
         explicit_expose = self.entity_config.get(state.entity_id, {}).get(CONF_EXPOSE)
 
         domain_exposed_by_default = (
             expose_by_default and state.domain in exposed_domains
         )
 
-        # Expose an entity if the entity's domain is exposed by default and
+        # Expose an entity by default if the entity's domain is exposed by default
+        # and the entity is not a config or diagnostic entity
+        entity_exposed_by_default = domain_exposed_by_default and not auxiliary_entity
+
+        # Expose an entity if the entity's is exposed by default and
         # the configuration doesn't explicitly exclude it from being
         # exposed, or if the entity is explicitly exposed
-        is_default_exposed = domain_exposed_by_default and explicit_expose is not False
+        is_default_exposed = entity_exposed_by_default and explicit_expose is not False
 
         return is_default_exposed or explicit_expose
 
diff --git a/tests/components/google_assistant/test_google_assistant.py b/tests/components/google_assistant/test_google_assistant.py
index 397b4c309a7..c17a05ddb3d 100644
--- a/tests/components/google_assistant/test_google_assistant.py
+++ b/tests/components/google_assistant/test_google_assistant.py
@@ -22,6 +22,8 @@ from homeassistant.const import CLOUD_NEVER_EXPOSED_ENTITIES
 
 from . import DEMO_DEVICES
 
+from tests.common import mock_registry
+
 API_PASSWORD = "test1234"
 
 PROJECT_ID = "hasstest-1234"
@@ -123,6 +125,28 @@ def hass_fixture(loop, hass):
 
 async def test_sync_request(hass_fixture, assistant_client, auth_header):
     """Test a sync request."""
+
+    entity_registry = mock_registry(hass_fixture)
+
+    entity_entry1 = entity_registry.async_get_or_create(
+        "switch",
+        "test",
+        "switch_config_id",
+        suggested_object_id="config_switch",
+        entity_category="config",
+    )
+    entity_entry2 = entity_registry.async_get_or_create(
+        "switch",
+        "test",
+        "switch_diagnostic_id",
+        suggested_object_id="diagnostic_switch",
+        entity_category="diagnostic",
+    )
+
+    # These should not show up in the sync request
+    hass_fixture.states.async_set(entity_entry1.entity_id, "on")
+    hass_fixture.states.async_set(entity_entry2.entity_id, "something_else")
+
     reqid = "5711642932632160983"
     data = {"requestId": reqid, "inputs": [{"intent": "action.devices.SYNC"}]}
     result = await assistant_client.post(