diff --git a/homeassistant/components/google_tasks/__init__.py b/homeassistant/components/google_tasks/__init__.py
index 2d570854ad4..494295f69f2 100644
--- a/homeassistant/components/google_tasks/__init__.py
+++ b/homeassistant/components/google_tasks/__init__.py
@@ -25,11 +25,17 @@ PLATFORMS: list[Platform] = [Platform.TODO]
 
 async def async_setup_entry(hass: HomeAssistant, entry: GoogleTasksConfigEntry) -> bool:
     """Set up Google Tasks from a config entry."""
-    implementation = (
-        await config_entry_oauth2_flow.async_get_config_entry_implementation(
-            hass, entry
+    try:
+        implementation = (
+            await config_entry_oauth2_flow.async_get_config_entry_implementation(
+                hass, entry
+            )
         )
-    )
+    except config_entry_oauth2_flow.ImplementationUnavailableError as err:
+        raise ConfigEntryNotReady(
+            translation_domain=DOMAIN,
+            translation_key="oauth2_implementation_unavailable",
+        ) from err
     session = config_entry_oauth2_flow.OAuth2Session(hass, entry, implementation)
     auth = api.AsyncConfigEntryAuth(hass, session)
     try:
diff --git a/homeassistant/components/google_tasks/strings.json b/homeassistant/components/google_tasks/strings.json
index d8ff18e0a7f..ea329c61bd1 100644
--- a/homeassistant/components/google_tasks/strings.json
+++ b/homeassistant/components/google_tasks/strings.json
@@ -42,5 +42,10 @@
         "title": "[%key:common::config_flow::title::reauth%]"
       }
     }
+  },
+  "exceptions": {
+    "oauth2_implementation_unavailable": {
+      "message": "[%key:common::exceptions::oauth2_implementation_unavailable::message%]"
+    }
   }
 }
diff --git a/tests/components/google_tasks/test_init.py b/tests/components/google_tasks/test_init.py
index e93e0d9c643..c1ed1cf609f 100644
--- a/tests/components/google_tasks/test_init.py
+++ b/tests/components/google_tasks/test_init.py
@@ -5,7 +5,7 @@ import http
 from http import HTTPStatus
 import json
 import time
-from unittest.mock import Mock
+from unittest.mock import Mock, patch
 
 from aiohttp import ClientError
 from httplib2 import Response
@@ -15,6 +15,9 @@ from homeassistant.components.google_tasks import DOMAIN
 from homeassistant.components.google_tasks.const import OAUTH2_TOKEN
 from homeassistant.config_entries import ConfigEntryState
 from homeassistant.core import HomeAssistant
+from homeassistant.helpers.config_entry_oauth2_flow import (
+    ImplementationUnavailableError,
+)
 
 from .conftest import LIST_TASK_LIST_RESPONSE, LIST_TASKS_RESPONSE_WATER
 
@@ -152,3 +155,20 @@ async def test_setup_error(
 
     assert not await integration_setup()
     assert config_entry.state is ConfigEntryState.SETUP_RETRY
+
+
+async def test_oauth_implementation_not_available(
+    hass: HomeAssistant,
+    config_entry: MockConfigEntry,
+) -> None:
+    """Test that unavailable OAuth implementation raises ConfigEntryNotReady."""
+    config_entry.add_to_hass(hass)
+
+    with patch(
+        "homeassistant.components.google_tasks.config_entry_oauth2_flow.async_get_config_entry_implementation",
+        side_effect=ImplementationUnavailableError,
+    ):
+        await hass.config_entries.async_setup(config_entry.entry_id)
+        await hass.async_block_till_done()
+
+    assert config_entry.state is ConfigEntryState.SETUP_RETRY