diff --git a/homeassistant/components/google_generative_ai_conversation/diagnostics.py b/homeassistant/components/google_generative_ai_conversation/diagnostics.py
new file mode 100644
index 00000000000..13643da7e00
--- /dev/null
+++ b/homeassistant/components/google_generative_ai_conversation/diagnostics.py
@@ -0,0 +1,26 @@
+"""Diagnostics support for Google Generative AI Conversation."""
+
+from __future__ import annotations
+
+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
+
+TO_REDACT = {CONF_API_KEY}
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant, entry: ConfigEntry
+) -> dict[str, Any]:
+    """Return diagnostics for a config entry."""
+    return async_redact_data(
+        {
+            "title": entry.title,
+            "data": entry.data,
+            "options": entry.options,
+        },
+        TO_REDACT,
+    )
diff --git a/script/hassfest/manifest.py b/script/hassfest/manifest.py
index cddfd5e101b..e92ec00b117 100644
--- a/script/hassfest/manifest.py
+++ b/script/hassfest/manifest.py
@@ -120,8 +120,6 @@ NO_DIAGNOSTICS = [
     "gdacs",
     "geonetnz_quakes",
     "google_assistant_sdk",
-    # diagnostics wouldn't really add anything (no data to provide)
-    "google_generative_ai_conversation",
     "hyperion",
     # Modbus is excluded because it doesn't have to have a config flow
     # according to ADR-0010, since it's a protocol integration. This
diff --git a/tests/components/google_generative_ai_conversation/snapshots/test_diagnostics.ambr b/tests/components/google_generative_ai_conversation/snapshots/test_diagnostics.ambr
new file mode 100644
index 00000000000..316bf74b72a
--- /dev/null
+++ b/tests/components/google_generative_ai_conversation/snapshots/test_diagnostics.ambr
@@ -0,0 +1,22 @@
+# serializer version: 1
+# name: test_diagnostics
+  dict({
+    'data': dict({
+      'api_key': '**REDACTED**',
+    }),
+    'options': dict({
+      'chat_model': 'models/gemini-1.5-flash-latest',
+      'dangerous_block_threshold': 'BLOCK_MEDIUM_AND_ABOVE',
+      'harassment_block_threshold': 'BLOCK_MEDIUM_AND_ABOVE',
+      'hate_block_threshold': 'BLOCK_MEDIUM_AND_ABOVE',
+      'max_tokens': 150,
+      'prompt': 'Speak like a pirate',
+      'recommended': False,
+      'sexual_block_threshold': 'BLOCK_MEDIUM_AND_ABOVE',
+      'temperature': 1.0,
+      'top_k': 64,
+      'top_p': 0.95,
+    }),
+    'title': 'Google Generative AI Conversation',
+  })
+# ---
diff --git a/tests/components/google_generative_ai_conversation/test_diagnostics.py b/tests/components/google_generative_ai_conversation/test_diagnostics.py
new file mode 100644
index 00000000000..ebc1b5e52a5
--- /dev/null
+++ b/tests/components/google_generative_ai_conversation/test_diagnostics.py
@@ -0,0 +1,59 @@
+"""Tests for the diagnostics data provided by the Google Generative AI Conversation integration."""
+
+from syrupy.assertion import SnapshotAssertion
+
+from homeassistant.components.google_generative_ai_conversation.const import (
+    CONF_CHAT_MODEL,
+    CONF_DANGEROUS_BLOCK_THRESHOLD,
+    CONF_HARASSMENT_BLOCK_THRESHOLD,
+    CONF_HATE_BLOCK_THRESHOLD,
+    CONF_MAX_TOKENS,
+    CONF_PROMPT,
+    CONF_RECOMMENDED,
+    CONF_SEXUAL_BLOCK_THRESHOLD,
+    CONF_TEMPERATURE,
+    CONF_TOP_K,
+    CONF_TOP_P,
+    RECOMMENDED_CHAT_MODEL,
+    RECOMMENDED_HARM_BLOCK_THRESHOLD,
+    RECOMMENDED_MAX_TOKENS,
+    RECOMMENDED_TEMPERATURE,
+    RECOMMENDED_TOP_K,
+    RECOMMENDED_TOP_P,
+)
+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,
+    mock_config_entry: MockConfigEntry,
+    snapshot: SnapshotAssertion,
+) -> None:
+    """Test diagnostics."""
+    mock_config_entry.add_to_hass(hass)
+    hass.config_entries.async_update_entry(
+        mock_config_entry,
+        options={
+            CONF_RECOMMENDED: False,
+            CONF_PROMPT: "Speak like a pirate",
+            CONF_TEMPERATURE: RECOMMENDED_TEMPERATURE,
+            CONF_CHAT_MODEL: RECOMMENDED_CHAT_MODEL,
+            CONF_TOP_P: RECOMMENDED_TOP_P,
+            CONF_TOP_K: RECOMMENDED_TOP_K,
+            CONF_MAX_TOKENS: RECOMMENDED_MAX_TOKENS,
+            CONF_HARASSMENT_BLOCK_THRESHOLD: RECOMMENDED_HARM_BLOCK_THRESHOLD,
+            CONF_HATE_BLOCK_THRESHOLD: RECOMMENDED_HARM_BLOCK_THRESHOLD,
+            CONF_SEXUAL_BLOCK_THRESHOLD: RECOMMENDED_HARM_BLOCK_THRESHOLD,
+            CONF_DANGEROUS_BLOCK_THRESHOLD: RECOMMENDED_HARM_BLOCK_THRESHOLD,
+        },
+    )
+    await hass.config_entries.async_setup(mock_config_entry.entry_id)
+    assert (
+        await get_diagnostics_for_config_entry(hass, hass_client, mock_config_entry)
+        == snapshot
+    )