diff --git a/homeassistant/components/qnap_qsw/diagnostics.py b/homeassistant/components/qnap_qsw/diagnostics.py
new file mode 100644
index 00000000000..3730bab24a8
--- /dev/null
+++ b/homeassistant/components/qnap_qsw/diagnostics.py
@@ -0,0 +1,37 @@
+"""Support for the QNAP QSW diagnostics."""
+from __future__ import annotations
+
+from typing import Any
+
+from aioqsw.const import QSD_MAC, QSD_SERIAL
+
+from homeassistant.components.diagnostics.util import async_redact_data
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.const import CONF_PASSWORD, CONF_UNIQUE_ID, CONF_USERNAME
+from homeassistant.core import HomeAssistant
+
+from .const import DOMAIN
+from .coordinator import QswUpdateCoordinator
+
+TO_REDACT_CONFIG = [
+    CONF_USERNAME,
+    CONF_PASSWORD,
+    CONF_UNIQUE_ID,
+]
+
+TO_REDACT_DATA = [
+    QSD_MAC,
+    QSD_SERIAL,
+]
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant, config_entry: ConfigEntry
+) -> dict[str, Any]:
+    """Return diagnostics for a config entry."""
+    coordinator: QswUpdateCoordinator = hass.data[DOMAIN][config_entry.entry_id]
+
+    return {
+        "config_entry": async_redact_data(config_entry.as_dict(), TO_REDACT_CONFIG),
+        "coord_data": async_redact_data(coordinator.data, TO_REDACT_DATA),
+    }
diff --git a/tests/components/qnap_qsw/test_diagnostics.py b/tests/components/qnap_qsw/test_diagnostics.py
new file mode 100644
index 00000000000..a4b5c1658e1
--- /dev/null
+++ b/tests/components/qnap_qsw/test_diagnostics.py
@@ -0,0 +1,123 @@
+"""The diagnostics tests for the QNAP QSW platform."""
+
+from aiohttp import ClientSession
+from aioqsw.const import (
+    API_ANOMALY,
+    API_BUILD_NUMBER,
+    API_FAN1_SPEED,
+    API_MAX_SWITCH_TEMP,
+    API_NUMBER,
+    API_PRODUCT,
+    API_RESULT,
+    API_SWITCH_TEMP,
+    API_UPTIME,
+    API_VERSION,
+    QSD_ANOMALY,
+    QSD_BUILD_NUMBER,
+    QSD_FAN1_SPEED,
+    QSD_FIRMWARE_CONDITION,
+    QSD_FIRMWARE_INFO,
+    QSD_MAC,
+    QSD_NUMBER,
+    QSD_PRODUCT,
+    QSD_SERIAL,
+    QSD_SYSTEM_BOARD,
+    QSD_SYSTEM_SENSOR,
+    QSD_SYSTEM_TIME,
+    QSD_TEMP,
+    QSD_TEMP_MAX,
+    QSD_UPTIME,
+    QSD_VERSION,
+)
+
+from homeassistant.components.diagnostics.const import REDACTED
+from homeassistant.components.qnap_qsw.const import DOMAIN
+from homeassistant.const import CONF_PASSWORD, CONF_URL, CONF_USERNAME
+from homeassistant.core import HomeAssistant
+
+from .util import (
+    CONFIG,
+    FIRMWARE_CONDITION_MOCK,
+    FIRMWARE_INFO_MOCK,
+    SYSTEM_BOARD_MOCK,
+    SYSTEM_SENSOR_MOCK,
+    SYSTEM_TIME_MOCK,
+    async_init_integration,
+)
+
+from tests.components.diagnostics import get_diagnostics_for_config_entry
+
+
+async def test_config_entry_diagnostics(
+    hass: HomeAssistant, hass_client: ClientSession
+) -> None:
+    """Test config entry diagnostics."""
+    await async_init_integration(hass)
+    assert hass.data[DOMAIN]
+
+    config_entry = hass.config_entries.async_entries(DOMAIN)[0]
+    diag = await get_diagnostics_for_config_entry(hass, hass_client, config_entry)
+
+    assert (
+        diag["config_entry"].items()
+        >= {
+            "data": {
+                CONF_PASSWORD: REDACTED,
+                CONF_URL: CONFIG[CONF_URL],
+                CONF_USERNAME: REDACTED,
+            },
+            "domain": DOMAIN,
+            "unique_id": REDACTED,
+        }.items()
+    )
+
+    fw_cond_diag = diag["coord_data"][QSD_FIRMWARE_CONDITION]
+    fw_cond_mock = FIRMWARE_CONDITION_MOCK[API_RESULT]
+    assert (
+        fw_cond_diag.items()
+        >= {
+            QSD_ANOMALY: fw_cond_mock[API_ANOMALY],
+        }.items()
+    )
+
+    fw_info_diag = diag["coord_data"][QSD_FIRMWARE_INFO]
+    fw_info_mock = FIRMWARE_INFO_MOCK[API_RESULT]
+    assert (
+        fw_info_diag.items()
+        >= {
+            QSD_BUILD_NUMBER: fw_info_mock[API_BUILD_NUMBER],
+            QSD_NUMBER: fw_info_mock[API_NUMBER],
+            QSD_VERSION: fw_info_mock[API_VERSION],
+        }.items()
+    )
+
+    sys_board_diag = diag["coord_data"][QSD_SYSTEM_BOARD]
+    sys_board_mock = SYSTEM_BOARD_MOCK[API_RESULT]
+    assert (
+        sys_board_diag.items()
+        >= {
+            QSD_MAC: REDACTED,
+            QSD_PRODUCT: sys_board_mock[API_PRODUCT],
+            QSD_SERIAL: REDACTED,
+        }.items()
+    )
+
+    sys_sensor_diag = diag["coord_data"][QSD_SYSTEM_SENSOR]
+    sys_sensor_mock = SYSTEM_SENSOR_MOCK[API_RESULT]
+    assert (
+        sys_sensor_diag.items()
+        >= {
+            QSD_FAN1_SPEED: sys_sensor_mock[API_FAN1_SPEED],
+            QSD_TEMP: sys_sensor_mock[API_SWITCH_TEMP],
+            QSD_TEMP_MAX: sys_sensor_mock[API_MAX_SWITCH_TEMP],
+        }.items()
+    )
+
+    sys_time_diag = diag["coord_data"][QSD_SYSTEM_TIME]
+    sys_time_mock = SYSTEM_TIME_MOCK[API_RESULT]
+    assert (
+        sys_time_diag.items()
+        >= {
+            QSD_UPTIME: sys_time_mock[API_UPTIME],
+        }.items()
+    )
diff --git a/tests/components/qnap_qsw/util.py b/tests/components/qnap_qsw/util.py
index 501c31f55e9..57b7b61a59d 100644
--- a/tests/components/qnap_qsw/util.py
+++ b/tests/components/qnap_qsw/util.py
@@ -127,8 +127,12 @@ async def async_init_integration(
 ) -> None:
     """Set up the QNAP QSW integration in Home Assistant."""
 
-    entry = MockConfigEntry(domain=DOMAIN, data=CONFIG)
-    entry.add_to_hass(hass)
+    config_entry = MockConfigEntry(
+        data=CONFIG,
+        domain=DOMAIN,
+        unique_id="qsw_unique_id",
+    )
+    config_entry.add_to_hass(hass)
 
     with patch(
         "homeassistant.components.qnap_qsw.QnapQswApi.get_firmware_condition",
@@ -149,5 +153,5 @@ async def async_init_integration(
         "homeassistant.components.qnap_qsw.QnapQswApi.post_users_login",
         return_value=USERS_LOGIN_MOCK,
     ):
-        await hass.config_entries.async_setup(entry.entry_id)
+        await hass.config_entries.async_setup(config_entry.entry_id)
         await hass.async_block_till_done()