diff --git a/homeassistant/components/google_assistant/diagnostics.py b/homeassistant/components/google_assistant/diagnostics.py
index 6cfaec99f6e..fd4347ddd2c 100644
--- a/homeassistant/components/google_assistant/diagnostics.py
+++ b/homeassistant/components/google_assistant/diagnostics.py
@@ -11,7 +11,11 @@ from homeassistant.helpers.typing import ConfigType
 
 from .const import CONF_SECURE_DEVICES_PIN, CONF_SERVICE_ACCOUNT, DATA_CONFIG, DOMAIN
 from .http import GoogleConfig
-from .smart_home import async_devices_sync_response, create_sync_response
+from .smart_home import (
+    async_devices_query_response,
+    async_devices_sync_response,
+    create_sync_response,
+)
 
 TO_REDACT = [
     "uuid",
@@ -32,9 +36,11 @@ async def async_get_config_entry_diagnostics(
     yaml_config: ConfigType = data[DATA_CONFIG]
     devices = await async_devices_sync_response(hass, config, REDACTED)
     sync = create_sync_response(REDACTED, devices)
+    query = await async_devices_query_response(hass, config, devices)
 
     return {
         "config_entry": async_redact_data(entry.as_dict(), TO_REDACT),
         "yaml_config": async_redact_data(yaml_config, TO_REDACT),
         "sync": async_redact_data(sync, TO_REDACT),
+        "query": async_redact_data(query, TO_REDACT),
     }
diff --git a/homeassistant/components/google_assistant/smart_home.py b/homeassistant/components/google_assistant/smart_home.py
index 75a3fd76b9b..c034e5fc6ca 100644
--- a/homeassistant/components/google_assistant/smart_home.py
+++ b/homeassistant/components/google_assistant/smart_home.py
@@ -130,6 +130,11 @@ async def async_devices_query(hass, data, payload):
         context=data.context,
     )
 
+    return await async_devices_query_response(hass, data.config, payload_devices)
+
+
+async def async_devices_query_response(hass, config, payload_devices):
+    """Generate the device serialization."""
     devices = {}
     for device in payload_devices:
         devid = device["id"]
@@ -139,7 +144,7 @@ async def async_devices_query(hass, data, payload):
             devices[devid] = {"online": False}
             continue
 
-        entity = GoogleEntity(hass, data.config, state)
+        entity = GoogleEntity(hass, config, state)
         try:
             devices[devid] = entity.query_serialize()
         except Exception:  # pylint: disable=broad-except
diff --git a/tests/components/google_assistant/test_diagnostics.py b/tests/components/google_assistant/test_diagnostics.py
index 13721c17f88..99a091f0bdc 100644
--- a/tests/components/google_assistant/test_diagnostics.py
+++ b/tests/components/google_assistant/test_diagnostics.py
@@ -80,6 +80,12 @@ async def test_diagnostics(hass: core.HomeAssistant, hass_client: Any):
                 },
             ],
         },
+        "query": {
+            "devices": {
+                "switch.ac": {"on": False, "online": True},
+                "switch.decorative_lights": {"on": True, "online": True},
+            }
+        },
         "yaml_config": {
             "expose_by_default": True,
             "exposed_domains": [