diff --git a/homeassistant/components/gios/diagnostics.py b/homeassistant/components/gios/diagnostics.py
new file mode 100644
index 00000000000..b056473fbec
--- /dev/null
+++ b/homeassistant/components/gios/diagnostics.py
@@ -0,0 +1,24 @@
+"""Diagnostics support for GIOS."""
+from __future__ import annotations
+
+from dataclasses import asdict
+
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.core import HomeAssistant
+
+from . import GiosDataUpdateCoordinator
+from .const import DOMAIN
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant, config_entry: ConfigEntry
+) -> dict:
+    """Return diagnostics for a config entry."""
+    coordinator: GiosDataUpdateCoordinator = hass.data[DOMAIN][config_entry.entry_id]
+
+    diagnostics_data = {
+        "config_entry": config_entry.as_dict(),
+        "coordinator_data": asdict(coordinator.data),
+    }
+
+    return diagnostics_data
diff --git a/tests/components/gios/fixtures/diagnostics_data.json b/tests/components/gios/fixtures/diagnostics_data.json
new file mode 100644
index 00000000000..1044c9887bb
--- /dev/null
+++ b/tests/components/gios/fixtures/diagnostics_data.json
@@ -0,0 +1,50 @@
+{
+  "aqi": {
+    "name": "AQI",
+    "id": null,
+    "index": null,
+    "value": "dobry"
+  },
+  "c6h6": {
+    "name": "benzen",
+    "id": 658,
+    "index": "bardzo dobry",
+    "value": 0.23789
+  },
+  "co": {
+    "name": "tlenek węgla",
+    "id": 660,
+    "index": "dobry",
+    "value": 251.874
+  },
+  "no2": {
+    "name": "dwutlenek azotu",
+    "id": 665,
+    "index": "dobry",
+    "value": 7.13411
+  },
+  "o3": {
+    "name": "ozon",
+    "id": 667,
+    "index": "dobry",
+    "value": 95.7768
+  },
+  "pm10": {
+    "name": "py\u0142 zawieszony PM10",
+    "id": 14395,
+    "index": "dobry",
+    "value": 16.8344
+  },
+  "pm25": {
+    "name": "py\u0142 zawieszony PM2.5",
+    "id": 670,
+    "index": "dobry",
+    "value": 4
+  },
+  "so2": {
+    "name": "dwutlenek siarki",
+    "id": 672,
+    "index": "bardzo dobry",
+    "value": 4.35478
+  }
+}
diff --git a/tests/components/gios/test_diagnostics.py b/tests/components/gios/test_diagnostics.py
new file mode 100644
index 00000000000..e72880feed7
--- /dev/null
+++ b/tests/components/gios/test_diagnostics.py
@@ -0,0 +1,33 @@
+"""Test GIOS diagnostics."""
+import json
+
+from tests.common import load_fixture
+from tests.components.diagnostics import get_diagnostics_for_config_entry
+from tests.components.gios import init_integration
+
+
+async def test_entry_diagnostics(hass, hass_client):
+    """Test config entry diagnostics."""
+    entry = await init_integration(hass)
+
+    coordinator_data = json.loads(load_fixture("diagnostics_data.json", "gios"))
+
+    result = await get_diagnostics_for_config_entry(hass, hass_client, entry)
+
+    assert result["config_entry"] == {
+        "entry_id": entry.entry_id,
+        "version": 1,
+        "domain": "gios",
+        "title": "Home",
+        "data": {
+            "station_id": 123,
+            "name": "Home",
+        },
+        "options": {},
+        "pref_disable_new_entities": False,
+        "pref_disable_polling": False,
+        "source": "user",
+        "unique_id": "123",
+        "disabled_by": None,
+    }
+    assert result["coordinator_data"] == coordinator_data