diff --git a/homeassistant/components/acaia/diagnostics.py b/homeassistant/components/acaia/diagnostics.py
new file mode 100644
index 00000000000..2d9f4511804
--- /dev/null
+++ b/homeassistant/components/acaia/diagnostics.py
@@ -0,0 +1,31 @@
+"""Diagnostics support for Acaia."""
+
+from __future__ import annotations
+
+from dataclasses import asdict
+from typing import Any
+
+from homeassistant.core import HomeAssistant
+
+from . import AcaiaConfigEntry
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant,
+    entry: AcaiaConfigEntry,
+) -> dict[str, Any]:
+    """Return diagnostics for a config entry."""
+    coordinator = entry.runtime_data
+    scale = coordinator.scale
+
+    # collect all data sources
+    return {
+        "model": scale.model,
+        "device_state": (
+            asdict(scale.device_state) if scale.device_state is not None else ""
+        ),
+        "mac": scale.mac,
+        "last_disconnect_time": scale.last_disconnect_time,
+        "timer": scale.timer,
+        "weight": scale.weight,
+    }
diff --git a/tests/components/acaia/conftest.py b/tests/components/acaia/conftest.py
index 7e3c19c6c5a..f1757a7f102 100644
--- a/tests/components/acaia/conftest.py
+++ b/tests/components/acaia/conftest.py
@@ -52,9 +52,10 @@ def mock_config_entry(hass: HomeAssistant) -> MockConfigEntry:
 @pytest.fixture
 async def init_integration(
     hass: HomeAssistant, mock_config_entry: MockConfigEntry, mock_scale: MagicMock
-) -> None:
+) -> MockConfigEntry:
     """Set up the acaia integration for testing."""
     await setup_integration(hass, mock_config_entry)
+    return mock_config_entry
 
 
 @pytest.fixture
@@ -70,6 +71,7 @@ def mock_scale() -> Generator[MagicMock]:
         scale.connected = True
         scale.mac = "aa:bb:cc:dd:ee:ff"
         scale.model = "Lunar"
+        scale.last_disconnect_time = "1732181388.1895587"
         scale.timer_running = True
         scale.heartbeat_task = None
         scale.process_queue_task = None
@@ -77,4 +79,5 @@ def mock_scale() -> Generator[MagicMock]:
             battery_level=42, units=AcaiaUnitOfMass.OUNCES
         )
         scale.weight = 123.45
+        scale.timer = 23
         yield scale
diff --git a/tests/components/acaia/snapshots/test_diagnostics.ambr b/tests/components/acaia/snapshots/test_diagnostics.ambr
new file mode 100644
index 00000000000..df5e4d36555
--- /dev/null
+++ b/tests/components/acaia/snapshots/test_diagnostics.ambr
@@ -0,0 +1,16 @@
+# serializer version: 1
+# name: test_diagnostics
+  dict({
+    'device_state': dict({
+      'auto_off_time': 0,
+      'battery_level': 42,
+      'beeps': True,
+      'units': 'ounces',
+    }),
+    'last_disconnect_time': '1732181388.1895587',
+    'mac': 'aa:bb:cc:dd:ee:ff',
+    'model': 'Lunar',
+    'timer': 23,
+    'weight': 123.45,
+  })
+# ---
diff --git a/tests/components/acaia/test_diagnostics.py b/tests/components/acaia/test_diagnostics.py
new file mode 100644
index 00000000000..77f6306b068
--- /dev/null
+++ b/tests/components/acaia/test_diagnostics.py
@@ -0,0 +1,22 @@
+"""Tests for the diagnostics data provided by the Acaia integration."""
+
+from syrupy import SnapshotAssertion
+
+from homeassistant.core import HomeAssistant
+
+from tests.common import MockConfigEntry
+from tests.components.diagnostics import get_diagnostics_for_config_entry
+from tests.typing import ClientSessionGenerator
+
+
+async def test_diagnostics(
+    hass: HomeAssistant,
+    hass_client: ClientSessionGenerator,
+    init_integration: MockConfigEntry,
+    snapshot: SnapshotAssertion,
+) -> None:
+    """Test diagnostics."""
+    assert (
+        await get_diagnostics_for_config_entry(hass, hass_client, init_integration)
+        == snapshot
+    )