diff --git a/homeassistant/components/cpuspeed/diagnostics.py b/homeassistant/components/cpuspeed/diagnostics.py
new file mode 100644
index 00000000000..a93c71430ef
--- /dev/null
+++ b/homeassistant/components/cpuspeed/diagnostics.py
@@ -0,0 +1,17 @@
+"""Diagnostics support for CPU Speed."""
+from __future__ import annotations
+
+from typing import Any
+
+from cpuinfo import cpuinfo
+
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.core import HomeAssistant
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant, entry: ConfigEntry
+) -> dict[str, Any]:
+    """Return diagnostics for a config entry."""
+    info: dict[str, Any] = cpuinfo.get_cpu_info()
+    return info
diff --git a/tests/components/cpuspeed/test_diagnostics.py b/tests/components/cpuspeed/test_diagnostics.py
new file mode 100644
index 00000000000..c8554390ea0
--- /dev/null
+++ b/tests/components/cpuspeed/test_diagnostics.py
@@ -0,0 +1,36 @@
+"""Tests for the diagnostics data provided by the CPU Speed integration."""
+from unittest.mock import patch
+
+from aiohttp import ClientSession
+
+from homeassistant.core import HomeAssistant
+
+from tests.common import MockConfigEntry
+from tests.components.diagnostics import get_diagnostics_for_config_entry
+
+
+async def test_diagnostics(
+    hass: HomeAssistant,
+    hass_client: ClientSession,
+    init_integration: MockConfigEntry,
+):
+    """Test diagnostics."""
+    info = {
+        "hz_actual": (3200000001, 0),
+        "arch_string_raw": "aargh",
+        "brand_raw": "Intel Ryzen 7",
+        "hz_advertised": (3600000001, 0),
+    }
+
+    with patch(
+        "homeassistant.components.cpuspeed.diagnostics.cpuinfo.get_cpu_info",
+        return_value=info,
+    ):
+        assert await get_diagnostics_for_config_entry(
+            hass, hass_client, init_integration
+        ) == {
+            "hz_actual": [3200000001, 0],
+            "arch_string_raw": "aargh",
+            "brand_raw": "Intel Ryzen 7",
+            "hz_advertised": [3600000001, 0],
+        }