diff --git a/homeassistant/components/tailscale/coordinator.py b/homeassistant/components/tailscale/coordinator.py
index daebfe807c1..d71116919e7 100644
--- a/homeassistant/components/tailscale/coordinator.py
+++ b/homeassistant/components/tailscale/coordinator.py
@@ -13,7 +13,7 @@ from homeassistant.helpers.update_coordinator import DataUpdateCoordinator
 from .const import CONF_TAILNET, DOMAIN, LOGGER, SCAN_INTERVAL
 
 
-class TailscaleDataUpdateCoordinator(DataUpdateCoordinator):
+class TailscaleDataUpdateCoordinator(DataUpdateCoordinator[dict[str, Device]]):
     """The Tailscale Data Update Coordinator."""
 
     config_entry: ConfigEntry
diff --git a/homeassistant/components/tailscale/diagnostics.py b/homeassistant/components/tailscale/diagnostics.py
new file mode 100644
index 00000000000..3c3393adc42
--- /dev/null
+++ b/homeassistant/components/tailscale/diagnostics.py
@@ -0,0 +1,37 @@
+"""Diagnostics support for Tailscale."""
+from __future__ import annotations
+
+import json
+from typing import Any
+
+from homeassistant.components.diagnostics import async_redact_data
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.const import CONF_API_KEY
+from homeassistant.core import HomeAssistant
+
+from .const import CONF_TAILNET, DOMAIN
+from .coordinator import TailscaleDataUpdateCoordinator
+
+TO_REDACT = {
+    CONF_API_KEY,
+    CONF_TAILNET,
+    "addresses",
+    "device_id",
+    "endpoints",
+    "hostname",
+    "machine_key",
+    "name",
+    "node_key",
+    "user",
+    "user",
+}
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant, entry: ConfigEntry
+) -> dict[str, Any]:
+    """Return diagnostics for a config entry."""
+    coordinator: TailscaleDataUpdateCoordinator = hass.data[DOMAIN][entry.entry_id]
+    # Round-trip via JSON to trigger serialization
+    devices = [json.loads(device.json()) for device in coordinator.data.values()]
+    return async_redact_data({"devices": devices}, TO_REDACT)
diff --git a/tests/components/tailscale/test_diagnostics.py b/tests/components/tailscale/test_diagnostics.py
new file mode 100644
index 00000000000..edea155c596
--- /dev/null
+++ b/tests/components/tailscale/test_diagnostics.py
@@ -0,0 +1,104 @@
+"""Tests for the diagnostics data provided by the Tailscale integration."""
+from aiohttp import ClientSession
+
+from homeassistant.components.diagnostics import REDACTED
+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."""
+    assert await get_diagnostics_for_config_entry(
+        hass, hass_client, init_integration
+    ) == {
+        "devices": [
+            {
+                "addresses": REDACTED,
+                "device_id": REDACTED,
+                "user": REDACTED,
+                "name": REDACTED,
+                "hostname": REDACTED,
+                "client_version": "1.12.3-td91ea7286-ge1bbbd90c",
+                "update_available": True,
+                "os": "iOS",
+                "created": "2021-08-19T09:25:22+00:00",
+                "last_seen": "2021-09-16T06:11:23+00:00",
+                "key_expiry_disabled": False,
+                "expires": "2022-02-15T09:25:22+00:00",
+                "authorized": True,
+                "is_external": False,
+                "machine_key": REDACTED,
+                "node_key": REDACTED,
+                "blocks_incoming_connections": False,
+                "enabled_routes": [],
+                "advertised_routes": [],
+                "client_connectivity": {
+                    "endpoints": REDACTED,
+                    "derp": "",
+                    "mapping_varies_by_dest_ip": False,
+                    "latency": {},
+                    "client_supports": {
+                        "hair_pinning": False,
+                        "ipv6": False,
+                        "pcp": False,
+                        "pmp": False,
+                        "udp": True,
+                        "upnp": False,
+                    },
+                },
+            },
+            {
+                "addresses": REDACTED,
+                "device_id": REDACTED,
+                "user": REDACTED,
+                "name": REDACTED,
+                "hostname": REDACTED,
+                "client_version": "1.14.0-t5cff36945-g809e87bba",
+                "update_available": True,
+                "os": "linux",
+                "created": "2021-08-29T09:49:06+00:00",
+                "last_seen": "2021-11-15T20:37:03+00:00",
+                "key_expiry_disabled": False,
+                "expires": "2022-02-25T09:49:06+00:00",
+                "authorized": True,
+                "is_external": False,
+                "machine_key": REDACTED,
+                "node_key": REDACTED,
+                "blocks_incoming_connections": False,
+                "enabled_routes": ["0.0.0.0/0", "10.10.10.0/23", "::/0"],
+                "advertised_routes": ["0.0.0.0/0", "10.10.10.0/23", "::/0"],
+                "client_connectivity": {
+                    "endpoints": REDACTED,
+                    "derp": "",
+                    "mapping_varies_by_dest_ip": False,
+                    "latency": {
+                        "Bangalore": {"latencyMs": 143.42505599999998},
+                        "Chicago": {"latencyMs": 101.123646},
+                        "Dallas": {"latencyMs": 136.85886},
+                        "Frankfurt": {"latencyMs": 18.968314},
+                        "London": {"preferred": True, "latencyMs": 14.314574},
+                        "New York City": {"latencyMs": 83.078912},
+                        "San Francisco": {"latencyMs": 148.215522},
+                        "Seattle": {"latencyMs": 181.553595},
+                        "Singapore": {"latencyMs": 164.566539},
+                        "São Paulo": {"latencyMs": 207.250179},
+                        "Tokyo": {"latencyMs": 226.90714300000002},
+                    },
+                    "client_supports": {
+                        "hair_pinning": True,
+                        "ipv6": False,
+                        "pcp": False,
+                        "pmp": False,
+                        "udp": True,
+                        "upnp": False,
+                    },
+                },
+            },
+        ]
+    }