diff --git a/homeassistant/components/devolo_home_control/diagnostics.py b/homeassistant/components/devolo_home_control/diagnostics.py
new file mode 100644
index 00000000000..412effcd5ed
--- /dev/null
+++ b/homeassistant/components/devolo_home_control/diagnostics.py
@@ -0,0 +1,49 @@
+"""Diagnostics support for devolo Home Control."""
+from __future__ import annotations
+
+from typing import Any
+
+from devolo_home_control_api.homecontrol import HomeControl
+
+from homeassistant.components.diagnostics import async_redact_data
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.const import CONF_PASSWORD, CONF_USERNAME
+from homeassistant.core import HomeAssistant
+
+from .const import DOMAIN
+
+TO_REDACT = {CONF_PASSWORD, CONF_USERNAME}
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant, entry: ConfigEntry
+) -> dict[str, Any]:
+    """Return diagnostics for a config entry."""
+    gateways: list[HomeControl] = hass.data[DOMAIN][entry.entry_id]["gateways"]
+
+    device_info = []
+    for gateway in gateways:
+        device_info.append(
+            {
+                "gateway": {
+                    "local_connection": gateway.gateway.local_connection,
+                    "firmware_version": gateway.gateway.firmware_version,
+                },
+                "devices": [
+                    {
+                        "device_id": device_id,
+                        "device_model_uid": properties.device_model_uid,
+                        "device_type": properties.device_type,
+                        "name": properties.name,
+                    }
+                    for device_id, properties in gateway.devices.items()
+                ],
+            }
+        )
+
+    diag_data = {
+        "entry": async_redact_data(entry.as_dict(), TO_REDACT),
+        "device_info": device_info,
+    }
+
+    return diag_data
diff --git a/tests/components/devolo_home_control/mocks.py b/tests/components/devolo_home_control/mocks.py
index aef687936e4..61a9f1c7d8c 100644
--- a/tests/components/devolo_home_control/mocks.py
+++ b/tests/components/devolo_home_control/mocks.py
@@ -115,6 +115,8 @@ class DeviceMock(Zwave):
         self.brand = "devolo"
         self.name = "Test Device"
         self.uid = "Test"
+        self.device_model_uid = "Test"
+        self.device_type = "Test"
         self.settings_property = {"general_device_settings": SettingsMock()}
         self.href = "https://www.mydevolo.com"
 
@@ -252,6 +254,9 @@ class HomeControlMock(HomeControl):
         """Initialize the mock."""
         self.devices = {}
         self.publisher = MagicMock()
+        self.gateway = MagicMock()
+        self.gateway.local_connection = True
+        self.gateway.firmware_version = "8.94.0"
 
     def websocket_disconnect(self, event: str = "") -> None:
         """Mock disconnect of the websocket."""
diff --git a/tests/components/devolo_home_control/test_diagnostics.py b/tests/components/devolo_home_control/test_diagnostics.py
new file mode 100644
index 00000000000..00c582ebf92
--- /dev/null
+++ b/tests/components/devolo_home_control/test_diagnostics.py
@@ -0,0 +1,65 @@
+"""Tests for the devolo Home Control diagnostics."""
+from __future__ import annotations
+
+from unittest.mock import patch
+
+from aiohttp import ClientSession
+
+from homeassistant.components.devolo_home_control.diagnostics import TO_REDACT
+from homeassistant.components.diagnostics import REDACTED
+from homeassistant.config_entries import ConfigEntryState
+from homeassistant.core import HomeAssistant
+
+from . import configure_integration
+from .mocks import HomeControlMock, HomeControlMockBinarySensor
+
+from tests.components.diagnostics import get_diagnostics_for_config_entry
+
+
+async def test_entry_diagnostics(hass: HomeAssistant, hass_client: ClientSession):
+    """Test setup and state change of a climate device."""
+    entry = configure_integration(hass)
+    gateway_1 = HomeControlMockBinarySensor()
+    gateway_2 = HomeControlMock()
+    with patch(
+        "homeassistant.components.devolo_home_control.HomeControl",
+        side_effect=[gateway_1, gateway_2],
+    ):
+        await hass.config_entries.async_setup(entry.entry_id)
+        await hass.async_block_till_done()
+
+        assert entry.state == ConfigEntryState.LOADED
+
+        entry_dict = entry.as_dict()
+        for key in TO_REDACT:
+            entry_dict["data"][key] = REDACTED
+
+        result = await get_diagnostics_for_config_entry(hass, hass_client, entry)
+
+        assert result == {
+            "entry": entry_dict,
+            "device_info": [
+                {
+                    "gateway": {
+                        "local_connection": gateway_1.gateway.local_connection,
+                        "firmware_version": gateway_1.gateway.firmware_version,
+                    },
+                    "devices": [
+                        {
+                            "device_id": device_id,
+                            "device_model_uid": properties.device_model_uid,
+                            "device_type": properties.device_type,
+                            "name": properties.name,
+                        }
+                        for device_id, properties in gateway_1.devices.items()
+                    ],
+                },
+                {
+                    "gateway": {
+                        "local_connection": gateway_2.gateway.local_connection,
+                        "firmware_version": gateway_2.gateway.firmware_version,
+                    },
+                    "devices": [],
+                },
+            ],
+        }