diff --git a/homeassistant/components/todoist/__init__.py b/homeassistant/components/todoist/__init__.py
index 78a9cb89624..12b75a40bae 100644
--- a/homeassistant/components/todoist/__init__.py
+++ b/homeassistant/components/todoist/__init__.py
@@ -1 +1,44 @@
-"""The todoist component."""
+"""The todoist integration."""
+
+import datetime
+import logging
+
+from todoist_api_python.api_async import TodoistAPIAsync
+
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.const import CONF_TOKEN, Platform
+from homeassistant.core import HomeAssistant
+
+from .const import DOMAIN
+from .coordinator import TodoistCoordinator
+
+_LOGGER = logging.getLogger(__name__)
+
+SCAN_INTERVAL = datetime.timedelta(minutes=1)
+
+
+PLATFORMS: list[Platform] = [Platform.CALENDAR]
+
+
+async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
+    """Set up todoist from a config entry."""
+
+    token = entry.data[CONF_TOKEN]
+    api = TodoistAPIAsync(token)
+    coordinator = TodoistCoordinator(hass, _LOGGER, SCAN_INTERVAL, api, token)
+    await coordinator.async_config_entry_first_refresh()
+
+    hass.data.setdefault(DOMAIN, {})
+    hass.data[DOMAIN][entry.entry_id] = coordinator
+
+    await hass.config_entries.async_forward_entry_setups(entry, PLATFORMS)
+
+    return True
+
+
+async def async_unload_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
+    """Unload a config entry."""
+    if unload_ok := await hass.config_entries.async_unload_platforms(entry, PLATFORMS):
+        hass.data[DOMAIN].pop(entry.entry_id)
+
+    return unload_ok
diff --git a/homeassistant/components/todoist/calendar.py b/homeassistant/components/todoist/calendar.py
index 544144018dd..40ceb71ee5f 100644
--- a/homeassistant/components/todoist/calendar.py
+++ b/homeassistant/components/todoist/calendar.py
@@ -17,8 +17,10 @@ from homeassistant.components.calendar import (
     CalendarEntity,
     CalendarEvent,
 )
+from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import CONF_ID, CONF_NAME, CONF_TOKEN, EVENT_HOMEASSISTANT_STOP
 from homeassistant.core import Event, HomeAssistant, ServiceCall, callback
+from homeassistant.exceptions import HomeAssistantError
 from homeassistant.helpers.aiohttp_client import async_get_clientsession
 import homeassistant.helpers.config_validation as cv
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
@@ -106,6 +108,23 @@ PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
 SCAN_INTERVAL = timedelta(minutes=1)
 
 
+async def async_setup_entry(
+    hass: HomeAssistant, entry: ConfigEntry, async_add_entities: AddEntitiesCallback
+) -> None:
+    """Set up the Todoist calendar platform config entry."""
+    coordinator = hass.data[DOMAIN][entry.entry_id]
+    projects = await coordinator.async_get_projects()
+    labels = await coordinator.async_get_labels()
+
+    entities = []
+    for project in projects:
+        project_data: ProjectData = {CONF_NAME: project.name, CONF_ID: project.id}
+        entities.append(TodoistProjectEntity(coordinator, project_data, labels))
+
+    async_add_entities(entities)
+    async_register_services(hass, coordinator)
+
+
 async def async_setup_platform(
     hass: HomeAssistant,
     config: ConfigType,
@@ -119,7 +138,7 @@ async def async_setup_platform(
     project_id_lookup = {}
 
     api = TodoistAPIAsync(token)
-    coordinator = TodoistCoordinator(hass, _LOGGER, SCAN_INTERVAL, api)
+    coordinator = TodoistCoordinator(hass, _LOGGER, SCAN_INTERVAL, api, token)
     await coordinator.async_refresh()
 
     async def _shutdown_coordinator(_: Event) -> None:
@@ -177,12 +196,29 @@ async def async_setup_platform(
 
     async_add_entities(project_devices, update_before_add=True)
 
+    async_register_services(hass, coordinator)
+
+
+def async_register_services(
+    hass: HomeAssistant, coordinator: TodoistCoordinator
+) -> None:
+    """Register services."""
+
+    if hass.services.has_service(DOMAIN, SERVICE_NEW_TASK):
+        return
+
     session = async_get_clientsession(hass)
 
     async def handle_new_task(call: ServiceCall) -> None:
         """Call when a user creates a new Todoist Task from Home Assistant."""
-        project_name = call.data[PROJECT_NAME]
-        project_id = project_id_lookup[project_name]
+        project_name = call.data[PROJECT_NAME].lower()
+        projects = await coordinator.async_get_projects()
+        project_id: str | None = None
+        for project in projects:
+            if project_name == project.name.lower():
+                project_id = project.id
+        if project_id is None:
+            raise HomeAssistantError(f"Invalid project name '{project_name}'")
 
         # Create the task
         content = call.data[CONTENT]
@@ -192,7 +228,7 @@ async def async_setup_platform(
             data["labels"] = task_labels
 
         if ASSIGNEE in call.data:
-            collaborators = await api.get_collaborators(project_id)
+            collaborators = await coordinator.api.get_collaborators(project_id)
             collaborator_id_lookup = {
                 collab.name.lower(): collab.id for collab in collaborators
             }
@@ -225,7 +261,7 @@ async def async_setup_platform(
             date_format = "%Y-%m-%dT%H:%M:%S"
             data["due_datetime"] = datetime.strftime(due_date, date_format)
 
-        api_task = await api.add_task(content, **data)
+        api_task = await coordinator.api.add_task(content, **data)
 
         # @NOTE: The rest-api doesn't support reminders, this works manually using
         # the sync api, in order to keep functional parity with the component.
@@ -263,7 +299,7 @@ async def async_setup_platform(
                     }
                 ]
             }
-            headers = create_headers(token=token, with_content=True)
+            headers = create_headers(token=coordinator.token, with_content=True)
             return await session.post(sync_url, headers=headers, json=reminder_data)
 
         if _reminder_due:
diff --git a/homeassistant/components/todoist/config_flow.py b/homeassistant/components/todoist/config_flow.py
new file mode 100644
index 00000000000..0a41ecb0463
--- /dev/null
+++ b/homeassistant/components/todoist/config_flow.py
@@ -0,0 +1,63 @@
+"""Config flow for todoist integration."""
+
+from http import HTTPStatus
+import logging
+from typing import Any
+
+from requests.exceptions import HTTPError
+from todoist_api_python.api_async import TodoistAPIAsync
+import voluptuous as vol
+
+from homeassistant import config_entries
+from homeassistant.const import CONF_TOKEN
+from homeassistant.data_entry_flow import FlowResult
+
+from .const import DOMAIN
+
+_LOGGER = logging.getLogger(__name__)
+
+SETTINGS_URL = "https://todoist.com/app/settings/integrations"
+
+STEP_USER_DATA_SCHEMA = vol.Schema(
+    {
+        vol.Required(CONF_TOKEN): str,
+    }
+)
+
+
+class ConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
+    """Handle a config flow for todoist."""
+
+    VERSION = 1
+
+    async def async_step_user(
+        self, user_input: dict[str, Any] | None = None
+    ) -> FlowResult:
+        """Handle the initial step."""
+        if self._async_current_entries():
+            return self.async_abort(reason="single_instance_allowed")
+
+        errors: dict[str, str] = {}
+        if user_input is not None:
+            api = TodoistAPIAsync(user_input[CONF_TOKEN])
+            try:
+                await api.get_tasks()
+            except HTTPError as err:
+                if err.response.status_code == HTTPStatus.UNAUTHORIZED:
+                    errors["base"] = "invalid_access_token"
+                else:
+                    errors["base"] = "cannot_connect"
+            except Exception:  # pylint: disable=broad-except
+                _LOGGER.exception("Unexpected exception")
+                errors["base"] = "unknown"
+            else:
+                await self.async_set_unique_id(user_input[CONF_TOKEN])
+                self._abort_if_unique_id_configured()
+                return self.async_create_entry(title="Todoist", data=user_input)
+
+        return self.async_show_form(
+            step_id="user",
+            data_schema=STEP_USER_DATA_SCHEMA,
+            errors=errors,
+            description_placeholders={"settings_url": SETTINGS_URL},
+        )
diff --git a/homeassistant/components/todoist/coordinator.py b/homeassistant/components/todoist/coordinator.py
index b573d1d1127..702c43883ea 100644
--- a/homeassistant/components/todoist/coordinator.py
+++ b/homeassistant/components/todoist/coordinator.py
@@ -3,7 +3,7 @@ from datetime import timedelta
 import logging
 
 from todoist_api_python.api_async import TodoistAPIAsync
-from todoist_api_python.models import Task
+from todoist_api_python.models import Label, Project, Task
 
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers.update_coordinator import DataUpdateCoordinator, UpdateFailed
@@ -18,10 +18,14 @@ class TodoistCoordinator(DataUpdateCoordinator[list[Task]]):
         logger: logging.Logger,
         update_interval: timedelta,
         api: TodoistAPIAsync,
+        token: str,
     ) -> None:
         """Initialize the Todoist coordinator."""
         super().__init__(hass, logger, name="Todoist", update_interval=update_interval)
         self.api = api
+        self._projects: list[Project] | None = None
+        self._labels: list[Label] | None = None
+        self.token = token
 
     async def _async_update_data(self) -> list[Task]:
         """Fetch tasks from the Todoist API."""
@@ -29,3 +33,15 @@ class TodoistCoordinator(DataUpdateCoordinator[list[Task]]):
             return await self.api.get_tasks()
         except Exception as err:
             raise UpdateFailed(f"Error communicating with API: {err}") from err
+
+    async def async_get_projects(self) -> list[Project]:
+        """Return todoist projects fetched at most once."""
+        if self._projects is None:
+            self._projects = await self.api.get_projects()
+        return self._projects
+
+    async def async_get_labels(self) -> list[Label]:
+        """Return todoist labels fetched at most once."""
+        if self._labels is None:
+            self._labels = await self.api.get_labels()
+        return self._labels
diff --git a/homeassistant/components/todoist/manifest.json b/homeassistant/components/todoist/manifest.json
index a83cdbe1b09..72d76108353 100644
--- a/homeassistant/components/todoist/manifest.json
+++ b/homeassistant/components/todoist/manifest.json
@@ -2,6 +2,7 @@
   "domain": "todoist",
   "name": "Todoist",
   "codeowners": ["@boralyl"],
+  "config_flow": true,
   "documentation": "https://www.home-assistant.io/integrations/todoist",
   "iot_class": "cloud_polling",
   "loggers": ["todoist"],
diff --git a/homeassistant/components/todoist/strings.json b/homeassistant/components/todoist/strings.json
index 1ed092e5cf6..123b5d07ed7 100644
--- a/homeassistant/components/todoist/strings.json
+++ b/homeassistant/components/todoist/strings.json
@@ -1,4 +1,23 @@
 {
+  "config": {
+    "step": {
+      "user": {
+        "data": {
+          "token": "[%key:common::config_flow::data::api_token%]"
+        },
+        "description": "Please entry your API token from your [Todoist Settings page]({settings_url})"
+      }
+    },
+    "error": {
+      "invalid_api_key": "[%key:common::config_flow::error::invalid_api_key%]"
+    },
+    "abort": {
+      "already_configured": "[%key:common::config_flow::abort::already_configured_account%]"
+    },
+    "create_entry": {
+      "default": "[%key:common::config_flow::create_entry::authenticated%]"
+    }
+  },
   "services": {
     "new_task": {
       "name": "New task",
diff --git a/homeassistant/generated/config_flows.py b/homeassistant/generated/config_flows.py
index 1557df8f33b..98935086b88 100644
--- a/homeassistant/generated/config_flows.py
+++ b/homeassistant/generated/config_flows.py
@@ -473,6 +473,7 @@ FLOWS = {
         "tibber",
         "tile",
         "tilt_ble",
+        "todoist",
         "tolo",
         "tomorrowio",
         "toon",
diff --git a/homeassistant/generated/integrations.json b/homeassistant/generated/integrations.json
index 7cad78a49fc..779ee92e9fe 100644
--- a/homeassistant/generated/integrations.json
+++ b/homeassistant/generated/integrations.json
@@ -5808,7 +5808,7 @@
     "todoist": {
       "name": "Todoist",
       "integration_type": "hub",
-      "config_flow": false,
+      "config_flow": true,
       "iot_class": "cloud_polling"
     },
     "tolo": {
diff --git a/tests/components/todoist/conftest.py b/tests/components/todoist/conftest.py
new file mode 100644
index 00000000000..6543e5b678f
--- /dev/null
+++ b/tests/components/todoist/conftest.py
@@ -0,0 +1,135 @@
+"""Common fixtures for the todoist tests."""
+from collections.abc import Generator
+from http import HTTPStatus
+from unittest.mock import AsyncMock, patch
+
+import pytest
+from requests.exceptions import HTTPError
+from requests.models import Response
+from todoist_api_python.models import Collaborator, Due, Label, Project, Task
+
+from homeassistant.components.todoist import DOMAIN
+from homeassistant.const import CONF_TOKEN
+from homeassistant.core import HomeAssistant
+from homeassistant.setup import async_setup_component
+from homeassistant.util import dt as dt_util
+
+from tests.common import MockConfigEntry
+
+SUMMARY = "A task"
+TOKEN = "some-token"
+
+
+@pytest.fixture
+def mock_setup_entry() -> Generator[AsyncMock, None, None]:
+    """Override async_setup_entry."""
+    with patch(
+        "homeassistant.components.todoist.async_setup_entry", return_value=True
+    ) as mock_setup_entry:
+        yield mock_setup_entry
+
+
+@pytest.fixture(name="due")
+def mock_due() -> Due:
+    """Mock a todoist Task Due date/time."""
+    return Due(
+        is_recurring=False, date=dt_util.now().strftime("%Y-%m-%d"), string="today"
+    )
+
+
+@pytest.fixture(name="task")
+def mock_task(due: Due) -> Task:
+    """Mock a todoist Task instance."""
+    return Task(
+        assignee_id="1",
+        assigner_id="1",
+        comment_count=0,
+        is_completed=False,
+        content=SUMMARY,
+        created_at="2021-10-01T00:00:00",
+        creator_id="1",
+        description="A task",
+        due=due,
+        id="1",
+        labels=["Label1"],
+        order=1,
+        parent_id=None,
+        priority=1,
+        project_id="12345",
+        section_id=None,
+        url="https://todoist.com",
+        sync_id=None,
+    )
+
+
+@pytest.fixture(name="api")
+def mock_api(task) -> AsyncMock:
+    """Mock the api state."""
+    api = AsyncMock()
+    api.get_projects.return_value = [
+        Project(
+            id="12345",
+            color="blue",
+            comment_count=0,
+            is_favorite=False,
+            name="Name",
+            is_shared=False,
+            url="",
+            is_inbox_project=False,
+            is_team_inbox=False,
+            order=1,
+            parent_id=None,
+            view_style="list",
+        )
+    ]
+    api.get_labels.return_value = [
+        Label(id="1", name="Label1", color="1", order=1, is_favorite=False)
+    ]
+    api.get_collaborators.return_value = [
+        Collaborator(email="user@gmail.com", id="1", name="user")
+    ]
+    api.get_tasks.return_value = [task]
+    return api
+
+
+@pytest.fixture(name="todoist_api_status")
+def mock_api_status() -> HTTPStatus | None:
+    """Fixture to inject an http status error."""
+    return None
+
+
+@pytest.fixture(autouse=True)
+def mock_api_side_effect(
+    api: AsyncMock, todoist_api_status: HTTPStatus | None
+) -> MockConfigEntry:
+    """Mock todoist configuration."""
+    if todoist_api_status:
+        response = Response()
+        response.status_code = todoist_api_status
+        api.get_tasks.side_effect = HTTPError(response=response)
+
+
+@pytest.fixture(name="todoist_config_entry")
+def mock_todoist_config_entry() -> MockConfigEntry:
+    """Mock todoist configuration."""
+    return MockConfigEntry(domain=DOMAIN, unique_id=TOKEN, data={CONF_TOKEN: TOKEN})
+
+
+@pytest.fixture(name="todoist_domain")
+def mock_todoist_domain() -> str:
+    """Mock todoist configuration."""
+    return DOMAIN
+
+
+@pytest.fixture(name="setup_integration")
+async def mock_setup_integration(
+    hass: HomeAssistant,
+    api: AsyncMock,
+    todoist_config_entry: MockConfigEntry | None,
+) -> None:
+    """Mock setup of the todoist integration."""
+    if todoist_config_entry is not None:
+        todoist_config_entry.add_to_hass(hass)
+    with patch("homeassistant.components.todoist.TodoistAPIAsync", return_value=api):
+        assert await async_setup_component(hass, DOMAIN, {})
+        yield
diff --git a/tests/components/todoist/test_calendar.py b/tests/components/todoist/test_calendar.py
index 921439fab45..45300e2e66c 100644
--- a/tests/components/todoist/test_calendar.py
+++ b/tests/components/todoist/test_calendar.py
@@ -7,7 +7,7 @@ import urllib
 import zoneinfo
 
 import pytest
-from todoist_api_python.models import Collaborator, Due, Label, Project, Task
+from todoist_api_python.models import Due
 
 from homeassistant import setup
 from homeassistant.components.todoist.const import (
@@ -24,9 +24,10 @@ from homeassistant.helpers import entity_registry as er
 from homeassistant.helpers.entity_component import async_update_entity
 from homeassistant.util import dt as dt_util
 
+from .conftest import SUMMARY
+
 from tests.typing import ClientSessionGenerator
 
-SUMMARY = "A task"
 # Set our timezone to CST/Regina so we can check calculations
 # This keeps UTC-6 all year round
 TZ_NAME = "America/Regina"
@@ -39,69 +40,6 @@ def set_time_zone(hass: HomeAssistant):
     hass.config.set_time_zone(TZ_NAME)
 
 
-@pytest.fixture(name="due")
-def mock_due() -> Due:
-    """Mock a todoist Task Due date/time."""
-    return Due(
-        is_recurring=False, date=dt_util.now().strftime("%Y-%m-%d"), string="today"
-    )
-
-
-@pytest.fixture(name="task")
-def mock_task(due: Due) -> Task:
-    """Mock a todoist Task instance."""
-    return Task(
-        assignee_id="1",
-        assigner_id="1",
-        comment_count=0,
-        is_completed=False,
-        content=SUMMARY,
-        created_at="2021-10-01T00:00:00",
-        creator_id="1",
-        description="A task",
-        due=due,
-        id="1",
-        labels=["Label1"],
-        order=1,
-        parent_id=None,
-        priority=1,
-        project_id="12345",
-        section_id=None,
-        url="https://todoist.com",
-        sync_id=None,
-    )
-
-
-@pytest.fixture(name="api")
-def mock_api(task) -> AsyncMock:
-    """Mock the api state."""
-    api = AsyncMock()
-    api.get_projects.return_value = [
-        Project(
-            id="12345",
-            color="blue",
-            comment_count=0,
-            is_favorite=False,
-            name="Name",
-            is_shared=False,
-            url="",
-            is_inbox_project=False,
-            is_team_inbox=False,
-            order=1,
-            parent_id=None,
-            view_style="list",
-        )
-    ]
-    api.get_labels.return_value = [
-        Label(id="1", name="Label1", color="1", order=1, is_favorite=False)
-    ]
-    api.get_collaborators.return_value = [
-        Collaborator(email="user@gmail.com", id="1", name="user")
-    ]
-    api.get_tasks.return_value = [task]
-    return api
-
-
 def get_events_url(entity: str, start: str, end: str) -> str:
     """Create a url to get events during the specified time range."""
     return f"/api/calendars/{entity}?start={urllib.parse.quote(start)}&end={urllib.parse.quote(end)}"
@@ -127,8 +65,8 @@ def mock_todoist_config() -> dict[str, Any]:
     return {}
 
 
-@pytest.fixture(name="setup_integration", autouse=True)
-async def mock_setup_integration(
+@pytest.fixture(name="setup_platform", autouse=True)
+async def mock_setup_platform(
     hass: HomeAssistant,
     api: AsyncMock,
     todoist_config: dict[str, Any],
@@ -215,7 +153,7 @@ async def test_update_entity_for_calendar_with_due_date_in_the_future(
     assert state.attributes["end_time"] == expected_end_time
 
 
-@pytest.mark.parametrize("setup_integration", [None])
+@pytest.mark.parametrize("setup_platform", [None])
 async def test_failed_coordinator_update(hass: HomeAssistant, api: AsyncMock) -> None:
     """Test a failed data coordinator update is handled correctly."""
     api.get_tasks.side_effect = Exception("API error")
@@ -417,3 +355,44 @@ async def test_task_due_datetime(
     )
     assert response.status == HTTPStatus.OK
     assert await response.json() == []
+
+
+@pytest.mark.parametrize(
+    ("due", "setup_platform"),
+    [
+        (
+            Due(
+                date="2023-03-30",
+                is_recurring=False,
+                string="Mar 30 6:00 PM",
+                datetime="2023-03-31T00:00:00Z",
+                timezone="America/Regina",
+            ),
+            None,
+        )
+    ],
+)
+async def test_config_entry(
+    hass: HomeAssistant,
+    setup_integration: None,
+    hass_client: ClientSessionGenerator,
+) -> None:
+    """Test for a calendar created with a config entry."""
+
+    await async_update_entity(hass, "calendar.name")
+    state = hass.states.get("calendar.name")
+    assert state
+
+    client = await hass_client()
+    response = await client.get(
+        get_events_url(
+            "calendar.name", "2023-03-30T08:00:00.000Z", "2023-03-31T08:00:00.000Z"
+        ),
+    )
+    assert response.status == HTTPStatus.OK
+    assert await response.json() == [
+        get_events_response(
+            {"dateTime": "2023-03-30T18:00:00-06:00"},
+            {"dateTime": "2023-03-31T18:00:00-06:00"},
+        )
+    ]
diff --git a/tests/components/todoist/test_config_flow.py b/tests/components/todoist/test_config_flow.py
new file mode 100644
index 00000000000..4175902da31
--- /dev/null
+++ b/tests/components/todoist/test_config_flow.py
@@ -0,0 +1,123 @@
+"""Test the todoist config flow."""
+
+from http import HTTPStatus
+from unittest.mock import AsyncMock, patch
+
+import pytest
+
+from homeassistant import config_entries
+from homeassistant.components.todoist.const import DOMAIN
+from homeassistant.const import CONF_TOKEN
+from homeassistant.core import HomeAssistant
+from homeassistant.data_entry_flow import FlowResultType
+
+from .conftest import TOKEN
+
+pytestmark = pytest.mark.usefixtures("mock_setup_entry")
+
+
+@pytest.fixture(autouse=True)
+async def patch_api(
+    api: AsyncMock,
+) -> None:
+    """Mock setup of the todoist integration."""
+    with patch(
+        "homeassistant.components.todoist.config_flow.TodoistAPIAsync", return_value=api
+    ):
+        yield
+
+
+async def test_form(
+    hass: HomeAssistant,
+    mock_setup_entry: AsyncMock,
+) -> None:
+    """Test we get the form."""
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN, context={"source": config_entries.SOURCE_USER}
+    )
+    assert result.get("type") == FlowResultType.FORM
+    assert not result.get("errors")
+
+    result2 = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        {
+            CONF_TOKEN: TOKEN,
+        },
+    )
+    await hass.async_block_till_done()
+
+    assert result2.get("type") == FlowResultType.CREATE_ENTRY
+    assert result2.get("title") == "Todoist"
+    assert result2.get("data") == {
+        CONF_TOKEN: TOKEN,
+    }
+    assert len(mock_setup_entry.mock_calls) == 1
+
+
+@pytest.mark.parametrize("todoist_api_status", [HTTPStatus.UNAUTHORIZED])
+async def test_form_invalid_auth(hass: HomeAssistant) -> None:
+    """Test we handle invalid auth."""
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN, context={"source": config_entries.SOURCE_USER}
+    )
+
+    result2 = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        {
+            CONF_TOKEN: TOKEN,
+        },
+    )
+
+    assert result2.get("type") == FlowResultType.FORM
+    assert result2.get("errors") == {"base": "invalid_access_token"}
+
+
+@pytest.mark.parametrize("todoist_api_status", [HTTPStatus.INTERNAL_SERVER_ERROR])
+async def test_form_cannot_connect(hass: HomeAssistant) -> None:
+    """Test we handle cannot connect error."""
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN, context={"source": config_entries.SOURCE_USER}
+    )
+
+    result2 = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        {
+            CONF_TOKEN: TOKEN,
+        },
+    )
+
+    assert result2.get("type") == FlowResultType.FORM
+    assert result2.get("errors") == {"base": "cannot_connect"}
+
+
+@pytest.mark.parametrize("todoist_api_status", [HTTPStatus.UNAUTHORIZED])
+async def test_unknown_error(hass: HomeAssistant, api: AsyncMock) -> None:
+    """Test we handle invalid auth."""
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN, context={"source": config_entries.SOURCE_USER}
+    )
+
+    api.get_tasks.side_effect = ValueError("unexpected")
+
+    result2 = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        {
+            CONF_TOKEN: TOKEN,
+        },
+    )
+
+    assert result2.get("type") == FlowResultType.FORM
+    assert result2.get("errors") == {"base": "unknown"}
+
+
+async def test_already_configured(hass: HomeAssistant, setup_integration: None) -> None:
+    """Test that only a single instance can be configured."""
+
+    entries = hass.config_entries.async_entries(DOMAIN)
+    assert len(entries) == 1
+
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN, context={"source": config_entries.SOURCE_USER}
+    )
+    assert result.get("type") == FlowResultType.ABORT
+    assert result.get("reason") == "single_instance_allowed"
diff --git a/tests/components/todoist/test_init.py b/tests/components/todoist/test_init.py
new file mode 100644
index 00000000000..cc64464df1d
--- /dev/null
+++ b/tests/components/todoist/test_init.py
@@ -0,0 +1,47 @@
+"""Unit tests for the Todoist integration."""
+from collections.abc import Generator
+from http import HTTPStatus
+from unittest.mock import AsyncMock, patch
+
+import pytest
+
+from homeassistant.components.todoist.const import DOMAIN
+from homeassistant.config_entries import ConfigEntryState
+from homeassistant.core import HomeAssistant
+
+from tests.common import MockConfigEntry
+
+
+@pytest.fixture(autouse=True)
+def mock_platforms() -> Generator[AsyncMock, None, None]:
+    """Override async_setup_entry."""
+    with patch(
+        "homeassistant.components.todoist.PLATFORMS", return_value=[]
+    ) as mock_setup_entry:
+        yield mock_setup_entry
+
+
+async def test_load_unload(
+    hass: HomeAssistant,
+    setup_integration: None,
+    todoist_config_entry: MockConfigEntry | None,
+) -> None:
+    """Test loading and unloading of the config entry."""
+    entries = hass.config_entries.async_entries(DOMAIN)
+    assert len(entries) == 1
+
+    assert todoist_config_entry.state == ConfigEntryState.LOADED
+
+    assert await hass.config_entries.async_unload(todoist_config_entry.entry_id)
+    assert todoist_config_entry.state == ConfigEntryState.NOT_LOADED
+
+
+@pytest.mark.parametrize("todoist_api_status", [HTTPStatus.INTERNAL_SERVER_ERROR])
+async def test_init_failure(
+    hass: HomeAssistant,
+    setup_integration: None,
+    api: AsyncMock,
+    todoist_config_entry: MockConfigEntry | None,
+) -> None:
+    """Test an initialization error on integration load."""
+    assert todoist_config_entry.state == ConfigEntryState.SETUP_RETRY