diff --git a/homeassistant/components/russound_rio/diagnostics.py b/homeassistant/components/russound_rio/diagnostics.py
new file mode 100644
index 00000000000..0e96413c41a
--- /dev/null
+++ b/homeassistant/components/russound_rio/diagnostics.py
@@ -0,0 +1,14 @@
+"""Diagnostics platform for Russound RIO."""
+
+from typing import Any
+
+from homeassistant.core import HomeAssistant
+
+from . import RussoundConfigEntry
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant, entry: RussoundConfigEntry
+) -> dict[str, Any]:
+    """Return diagnostics for the provided config entry."""
+    return entry.runtime_data.state
diff --git a/tests/components/russound_rio/conftest.py b/tests/components/russound_rio/conftest.py
index 09cccd7d83f..deb7bfccdf0 100644
--- a/tests/components/russound_rio/conftest.py
+++ b/tests/components/russound_rio/conftest.py
@@ -54,6 +54,7 @@ def mock_russound_client() -> Generator[AsyncMock]:
             int(k): Source.from_dict(v)
             for k, v in load_json_object_fixture("get_sources.json", DOMAIN).items()
         }
+        client.state = load_json_object_fixture("get_state.json", DOMAIN)
         for k, v in zones.items():
             v.device_str = zone_device_str(1, k)
             v.fetch_current_source = Mock(
diff --git a/tests/components/russound_rio/fixtures/get_state.json b/tests/components/russound_rio/fixtures/get_state.json
new file mode 100644
index 00000000000..931b7611d01
--- /dev/null
+++ b/tests/components/russound_rio/fixtures/get_state.json
@@ -0,0 +1,75 @@
+{
+  "S": {
+    "3": {
+      "name": "Streamer",
+      "type": "Misc Audio"
+    },
+    "2": {
+      "name": "Liv. Rm TV",
+      "type": "Misc Audio"
+    },
+    "5": {
+      "name": "Source 5",
+      "type": null
+    },
+    "4": {
+      "name": "Basement TV",
+      "type": null
+    },
+    "1": {
+      "name": "Tuner",
+      "type": "DMS-3.1 Media Streamer",
+      "channelName": null,
+      "coverArtURL": null,
+      "mode": "Unknown",
+      "shuffleMode": null,
+      "repeatMode": null,
+      "volume": "0",
+      "rating": null,
+      "playlistName": "Please Wait...",
+      "artistName": null,
+      "albumName": null,
+      "songName": "Connecting to media source."
+    },
+    "6": {
+      "name": "Source 6",
+      "type": null
+    },
+    "8": {
+      "name": "Source 8",
+      "type": null
+    },
+    "7": {
+      "name": "Source 7",
+      "type": null
+    }
+  },
+  "System": {
+    "status": "OFF"
+  },
+  "C": {
+    "1": {
+      "Z": {
+        "1": {
+          "name": "Deck",
+          "treble": "0",
+          "balance": "0",
+          "loudness": "OFF",
+          "turnOnVolume": "10",
+          "doNotDisturb": "OFF",
+          "currentSource": "2",
+          "volume": "0",
+          "status": "OFF",
+          "mute": "OFF",
+          "partyMode": "OFF",
+          "bass": "0",
+          "page": "OFF",
+          "sharedSource": "OFF",
+          "sleepTimeRemaining": "0",
+          "lastError": null,
+          "enabled_sources": [3, 2]
+        }
+      }
+    }
+  }
+}
diff --git a/tests/components/russound_rio/snapshots/test_diagnostics.ambr b/tests/components/russound_rio/snapshots/test_diagnostics.ambr
new file mode 100644
index 00000000000..ff3a8bf757f
--- /dev/null
+++ b/tests/components/russound_rio/snapshots/test_diagnostics.ambr
@@ -0,0 +1,81 @@
+# serializer version: 1
+# name: test_entry_diagnostics
+  dict({
+    'C': dict({
+      '1': dict({
+        'Z': dict({
+          '1': dict({
+            'balance': '0',
+            'bass': '0',
+            'currentSource': '2',
+            'doNotDisturb': 'OFF',
+            'enabled_sources': list([
+              3,
+              2,
+            ]),
+            'lastError': None,
+            'loudness': 'OFF',
+            'mute': 'OFF',
+            'name': 'Deck',
+            'page': 'OFF',
+            'partyMode': 'OFF',
+            'sharedSource': 'OFF',
+            'sleepTimeRemaining': '0',
+            'status': 'OFF',
+            'treble': '0',
+            'turnOnVolume': '10',
+            'volume': '0',
+          }),
+        }),
+      }),
+    }),
+    'S': dict({
+      '1': dict({
+        'albumName': None,
+        'artistName': None,
+        'channelName': None,
+        'coverArtURL': None,
+        'mode': 'Unknown',
+        'name': 'Tuner',
+        'playlistName': 'Please Wait...',
+        'rating': None,
+        'repeatMode': None,
+        'shuffleMode': None,
+        'songName': 'Connecting to media source.',
+        'type': 'DMS-3.1 Media Streamer',
+        'volume': '0',
+      }),
+      '2': dict({
+        'name': 'Liv. Rm TV',
+        'type': 'Misc Audio',
+      }),
+      '3': dict({
+        'name': 'Streamer',
+        'type': 'Misc Audio',
+      }),
+      '4': dict({
+        'name': 'Basement TV',
+        'type': None,
+      }),
+      '5': dict({
+        'name': 'Source 5',
+        'type': None,
+      }),
+      '6': dict({
+        'name': 'Source 6',
+        'type': None,
+      }),
+      '7': dict({
+        'name': 'Source 7',
+        'type': None,
+      }),
+      '8': dict({
+        'name': 'Source 8',
+        'type': None,
+      }),
+    }),
+    'System': dict({
+      'status': 'OFF',
+    }),
+  })
+# ---
diff --git a/tests/components/russound_rio/test_diagnostics.py b/tests/components/russound_rio/test_diagnostics.py
new file mode 100644
index 00000000000..c6c5441128d
--- /dev/null
+++ b/tests/components/russound_rio/test_diagnostics.py
@@ -0,0 +1,29 @@
+"""Tests for the diagnostics data provided by the Russound RIO integration."""
+
+from unittest.mock import AsyncMock
+
+from syrupy import SnapshotAssertion
+
+from homeassistant.core import HomeAssistant
+
+from . import setup_integration
+
+from tests.common import MockConfigEntry
+from tests.components.diagnostics import get_diagnostics_for_config_entry
+from tests.typing import ClientSessionGenerator
+
+
+async def test_entry_diagnostics(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_russound_client: AsyncMock,
+    hass_client: ClientSessionGenerator,
+    snapshot: SnapshotAssertion,
+) -> None:
+    """Test config entry diagnostics."""
+    await setup_integration(hass, mock_config_entry)
+
+    result = await get_diagnostics_for_config_entry(
+        hass, hass_client, mock_config_entry
+    )
+    assert result == snapshot