diff --git a/homeassistant/components/energyzero/diagnostics.py b/homeassistant/components/energyzero/diagnostics.py
new file mode 100644
index 00000000000..5e3e402efbf
--- /dev/null
+++ b/homeassistant/components/energyzero/diagnostics.py
@@ -0,0 +1,58 @@
+"""Diagnostics support for EnergyZero."""
+from __future__ import annotations
+
+from datetime import timedelta
+from typing import Any
+
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.core import HomeAssistant
+
+from . import EnergyZeroDataUpdateCoordinator
+from .const import DOMAIN
+from .coordinator import EnergyZeroData
+
+
+def get_gas_price(data: EnergyZeroData, hours: int) -> float | None:
+    """Get the gas price for a given hour.
+
+    Args:
+        data: The data object.
+        hours: The number of hours to add to the current time.
+
+    Returns:
+        The gas market price value.
+    """
+    if not data.gas_today:
+        return None
+    return data.gas_today.price_at_time(
+        data.gas_today.utcnow() + timedelta(hours=hours)
+    )
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant, entry: ConfigEntry
+) -> dict[str, Any]:
+    """Return diagnostics for a config entry."""
+    coordinator: EnergyZeroDataUpdateCoordinator = hass.data[DOMAIN][entry.entry_id]
+
+    return {
+        "entry": {
+            "title": entry.title,
+        },
+        "energy": {
+            "current_hour_price": coordinator.data.energy_today.current_price,
+            "next_hour_price": coordinator.data.energy_today.price_at_time(
+                coordinator.data.energy_today.utcnow() + timedelta(hours=1)
+            ),
+            "average_price": coordinator.data.energy_today.average_price,
+            "max_price": coordinator.data.energy_today.extreme_prices[1],
+            "min_price": coordinator.data.energy_today.extreme_prices[0],
+            "highest_price_time": coordinator.data.energy_today.highest_price_time,
+            "lowest_price_time": coordinator.data.energy_today.lowest_price_time,
+            "percentage_of_max": coordinator.data.energy_today.pct_of_max_price,
+        },
+        "gas": {
+            "current_hour_price": get_gas_price(coordinator.data, 0),
+            "next_hour_price": get_gas_price(coordinator.data, 1),
+        },
+    }
diff --git a/homeassistant/components/energyzero/manifest.json b/homeassistant/components/energyzero/manifest.json
index d3f29d6a026..f0a76ab3baf 100644
--- a/homeassistant/components/energyzero/manifest.json
+++ b/homeassistant/components/energyzero/manifest.json
@@ -5,5 +5,6 @@
   "documentation": "https://www.home-assistant.io/integrations/energyzero",
   "requirements": ["energyzero==0.3.1"],
   "codeowners": ["@klaasnicolaas"],
-  "iot_class": "cloud_polling"
+  "iot_class": "cloud_polling",
+  "quality_scale": "platinum"
 }
diff --git a/tests/components/energyzero/test_diagnostics.py b/tests/components/energyzero/test_diagnostics.py
new file mode 100644
index 00000000000..e58ca9bc0bf
--- /dev/null
+++ b/tests/components/energyzero/test_diagnostics.py
@@ -0,0 +1,86 @@
+"""Tests for the diagnostics data provided by the EnergyZero integration."""
+from unittest.mock import MagicMock
+
+from aiohttp import ClientSession
+from energyzero import EnergyZeroNoDataError
+import pytest
+
+from homeassistant.components.homeassistant import SERVICE_UPDATE_ENTITY
+from homeassistant.const import ATTR_ENTITY_ID
+from homeassistant.core import HomeAssistant
+from homeassistant.setup import async_setup_component
+
+from tests.common import MockConfigEntry
+from tests.components.diagnostics import get_diagnostics_for_config_entry
+
+
+@pytest.mark.freeze_time("2022-12-07 15:00:00")
+async def test_diagnostics(
+    hass: HomeAssistant,
+    hass_client: ClientSession,
+    init_integration: MockConfigEntry,
+) -> None:
+    """Test diagnostics."""
+    assert await get_diagnostics_for_config_entry(
+        hass, hass_client, init_integration
+    ) == {
+        "entry": {
+            "title": "energy",
+        },
+        "energy": {
+            "current_hour_price": 0.49,
+            "next_hour_price": 0.55,
+            "average_price": 0.37,
+            "max_price": 0.55,
+            "min_price": 0.26,
+            "highest_price_time": "2022-12-07T16:00:00+00:00",
+            "lowest_price_time": "2022-12-07T02:00:00+00:00",
+            "percentage_of_max": 89.09,
+        },
+        "gas": {
+            "current_hour_price": 1.47,
+            "next_hour_price": 1.47,
+        },
+    }
+
+
+@pytest.mark.freeze_time("2022-12-07 15:00:00")
+async def test_diagnostics_no_gas_today(
+    hass: HomeAssistant,
+    hass_client: ClientSession,
+    mock_energyzero: MagicMock,
+    init_integration: MockConfigEntry,
+) -> None:
+    """Test diagnostics, no gas sensors available."""
+    await async_setup_component(hass, "homeassistant", {})
+    mock_energyzero.gas_prices.side_effect = EnergyZeroNoDataError
+
+    await hass.services.async_call(
+        "homeassistant",
+        SERVICE_UPDATE_ENTITY,
+        {ATTR_ENTITY_ID: ["sensor.energyzero_today_gas_current_hour_price"]},
+        blocking=True,
+    )
+    await hass.async_block_till_done()
+
+    assert await get_diagnostics_for_config_entry(
+        hass, hass_client, init_integration
+    ) == {
+        "entry": {
+            "title": "energy",
+        },
+        "energy": {
+            "current_hour_price": 0.49,
+            "next_hour_price": 0.55,
+            "average_price": 0.37,
+            "max_price": 0.55,
+            "min_price": 0.26,
+            "highest_price_time": "2022-12-07T16:00:00+00:00",
+            "lowest_price_time": "2022-12-07T02:00:00+00:00",
+            "percentage_of_max": 89.09,
+        },
+        "gas": {
+            "current_hour_price": None,
+            "next_hour_price": None,
+        },
+    }