diff --git a/.strict-typing b/.strict-typing
index 062eee858d5..a6a8a4c3e22 100644
--- a/.strict-typing
+++ b/.strict-typing
@@ -21,6 +21,7 @@ homeassistant.components.camera.*
 homeassistant.components.canary.*
 homeassistant.components.cover.*
 homeassistant.components.device_automation.*
+homeassistant.components.device_tracker.*
 homeassistant.components.elgato.*
 homeassistant.components.fitbit.*
 homeassistant.components.fritzbox.*
diff --git a/homeassistant/components/device_tracker/__init__.py b/homeassistant/components/device_tracker/__init__.py
index dfdfd678c0f..fa537d4af53 100644
--- a/homeassistant/components/device_tracker/__init__.py
+++ b/homeassistant/components/device_tracker/__init__.py
@@ -37,12 +37,12 @@ from .legacy import (  # noqa: F401
 
 
 @bind_hass
-def is_on(hass: HomeAssistant, entity_id: str):
+def is_on(hass: HomeAssistant, entity_id: str) -> bool:
     """Return the state if any or a specified device is home."""
     return hass.states.is_state(entity_id, STATE_HOME)
 
 
-async def async_setup(hass: HomeAssistant, config: ConfigType):
+async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
     """Set up the device tracker."""
     await async_setup_legacy_integration(hass, config)
 
diff --git a/homeassistant/components/device_tracker/config_entry.py b/homeassistant/components/device_tracker/config_entry.py
index 6f4e608520c..97b79306e7b 100644
--- a/homeassistant/components/device_tracker/config_entry.py
+++ b/homeassistant/components/device_tracker/config_entry.py
@@ -4,6 +4,7 @@ from __future__ import annotations
 from typing import final
 
 from homeassistant.components import zone
+from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import (
     ATTR_BATTERY_LEVEL,
     ATTR_GPS_ACCURACY,
@@ -12,13 +13,15 @@ from homeassistant.const import (
     STATE_HOME,
     STATE_NOT_HOME,
 )
+from homeassistant.core import HomeAssistant
 from homeassistant.helpers.entity import Entity
 from homeassistant.helpers.entity_component import EntityComponent
+from homeassistant.helpers.typing import StateType
 
 from .const import ATTR_HOST_NAME, ATTR_IP, ATTR_MAC, ATTR_SOURCE_TYPE, DOMAIN, LOGGER
 
 
-async def async_setup_entry(hass, entry):
+async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     """Set up an entry."""
     component: EntityComponent | None = hass.data.get(DOMAIN)
 
@@ -28,16 +31,17 @@ async def async_setup_entry(hass, entry):
     return await component.async_setup_entry(entry)
 
 
-async def async_unload_entry(hass, entry):
+async def async_unload_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     """Unload an entry."""
-    return await hass.data[DOMAIN].async_unload_entry(entry)
+    component: EntityComponent = hass.data[DOMAIN]
+    return await component.async_unload_entry(entry)
 
 
 class BaseTrackerEntity(Entity):
     """Represent a tracked device."""
 
     @property
-    def battery_level(self):
+    def battery_level(self) -> int | None:
         """Return the battery level of the device.
 
         Percentage from 0-100.
@@ -45,16 +49,16 @@ class BaseTrackerEntity(Entity):
         return None
 
     @property
-    def source_type(self):
+    def source_type(self) -> str:
         """Return the source type, eg gps or router, of the device."""
         raise NotImplementedError
 
     @property
-    def state_attributes(self):
+    def state_attributes(self) -> dict[str, StateType]:
         """Return the device state attributes."""
-        attr = {ATTR_SOURCE_TYPE: self.source_type}
+        attr: dict[str, StateType] = {ATTR_SOURCE_TYPE: self.source_type}
 
-        if self.battery_level:
+        if self.battery_level is not None:
             attr[ATTR_BATTERY_LEVEL] = self.battery_level
 
         return attr
@@ -64,17 +68,17 @@ class TrackerEntity(BaseTrackerEntity):
     """Base class for a tracked device."""
 
     @property
-    def should_poll(self):
+    def should_poll(self) -> bool:
         """No polling for entities that have location pushed."""
         return False
 
     @property
-    def force_update(self):
+    def force_update(self) -> bool:
         """All updates need to be written to the state machine if we're not polling."""
         return not self.should_poll
 
     @property
-    def location_accuracy(self):
+    def location_accuracy(self) -> int:
         """Return the location accuracy of the device.
 
         Value in meters.
@@ -97,9 +101,9 @@ class TrackerEntity(BaseTrackerEntity):
         raise NotImplementedError
 
     @property
-    def state(self):
+    def state(self) -> str | None:
         """Return the state of the device."""
-        if self.location_name:
+        if self.location_name is not None:
             return self.location_name
 
         if self.latitude is not None and self.longitude is not None:
@@ -118,11 +122,11 @@ class TrackerEntity(BaseTrackerEntity):
 
     @final
     @property
-    def state_attributes(self):
+    def state_attributes(self) -> dict[str, StateType]:
         """Return the device state attributes."""
-        attr = {}
+        attr: dict[str, StateType] = {}
         attr.update(super().state_attributes)
-        if self.latitude is not None:
+        if self.latitude is not None and self.longitude is not None:
             attr[ATTR_LATITUDE] = self.latitude
             attr[ATTR_LONGITUDE] = self.longitude
             attr[ATTR_GPS_ACCURACY] = self.location_accuracy
@@ -162,9 +166,9 @@ class ScannerEntity(BaseTrackerEntity):
 
     @final
     @property
-    def state_attributes(self):
+    def state_attributes(self) -> dict[str, StateType]:
         """Return the device state attributes."""
-        attr = {}
+        attr: dict[str, StateType] = {}
         attr.update(super().state_attributes)
         if self.ip_address is not None:
             attr[ATTR_IP] = self.ip_address
diff --git a/homeassistant/components/device_tracker/const.py b/homeassistant/components/device_tracker/const.py
index aa1b349ef12..09102372db6 100644
--- a/homeassistant/components/device_tracker/const.py
+++ b/homeassistant/components/device_tracker/const.py
@@ -1,37 +1,38 @@
 """Device tracker constants."""
 from datetime import timedelta
 import logging
+from typing import Final
 
-LOGGER = logging.getLogger(__package__)
+LOGGER: Final = logging.getLogger(__package__)
 
-DOMAIN = "device_tracker"
+DOMAIN: Final = "device_tracker"
 
-PLATFORM_TYPE_LEGACY = "legacy"
-PLATFORM_TYPE_ENTITY = "entity_platform"
+PLATFORM_TYPE_LEGACY: Final = "legacy"
+PLATFORM_TYPE_ENTITY: Final = "entity_platform"
 
-SOURCE_TYPE_GPS = "gps"
-SOURCE_TYPE_ROUTER = "router"
-SOURCE_TYPE_BLUETOOTH = "bluetooth"
-SOURCE_TYPE_BLUETOOTH_LE = "bluetooth_le"
+SOURCE_TYPE_GPS: Final = "gps"
+SOURCE_TYPE_ROUTER: Final = "router"
+SOURCE_TYPE_BLUETOOTH: Final = "bluetooth"
+SOURCE_TYPE_BLUETOOTH_LE: Final = "bluetooth_le"
 
-CONF_SCAN_INTERVAL = "interval_seconds"
-SCAN_INTERVAL = timedelta(seconds=12)
+CONF_SCAN_INTERVAL: Final = "interval_seconds"
+SCAN_INTERVAL: Final = timedelta(seconds=12)
 
-CONF_TRACK_NEW = "track_new_devices"
-DEFAULT_TRACK_NEW = True
+CONF_TRACK_NEW: Final = "track_new_devices"
+DEFAULT_TRACK_NEW: Final = True
 
-CONF_CONSIDER_HOME = "consider_home"
-DEFAULT_CONSIDER_HOME = timedelta(seconds=180)
+CONF_CONSIDER_HOME: Final = "consider_home"
+DEFAULT_CONSIDER_HOME: Final = timedelta(seconds=180)
 
-CONF_NEW_DEVICE_DEFAULTS = "new_device_defaults"
+CONF_NEW_DEVICE_DEFAULTS: Final = "new_device_defaults"
 
-ATTR_ATTRIBUTES = "attributes"
-ATTR_BATTERY = "battery"
-ATTR_DEV_ID = "dev_id"
-ATTR_GPS = "gps"
-ATTR_HOST_NAME = "host_name"
-ATTR_LOCATION_NAME = "location_name"
-ATTR_MAC = "mac"
-ATTR_SOURCE_TYPE = "source_type"
-ATTR_CONSIDER_HOME = "consider_home"
-ATTR_IP = "ip"
+ATTR_ATTRIBUTES: Final = "attributes"
+ATTR_BATTERY: Final = "battery"
+ATTR_DEV_ID: Final = "dev_id"
+ATTR_GPS: Final = "gps"
+ATTR_HOST_NAME: Final = "host_name"
+ATTR_LOCATION_NAME: Final = "location_name"
+ATTR_MAC: Final = "mac"
+ATTR_SOURCE_TYPE: Final = "source_type"
+ATTR_CONSIDER_HOME: Final = "consider_home"
+ATTR_IP: Final = "ip"
diff --git a/homeassistant/components/device_tracker/device_trigger.py b/homeassistant/components/device_tracker/device_trigger.py
index 81a16545c74..3c7f9ac35ad 100644
--- a/homeassistant/components/device_tracker/device_trigger.py
+++ b/homeassistant/components/device_tracker/device_trigger.py
@@ -1,6 +1,8 @@
 """Provides device automations for Device Tracker."""
 from __future__ import annotations
 
+from typing import Final
+
 import voluptuous as vol
 
 from homeassistant.components.automation import AutomationActionType
@@ -21,9 +23,9 @@ from homeassistant.helpers.typing import ConfigType
 
 from . import DOMAIN
 
-TRIGGER_TYPES = {"enters", "leaves"}
+TRIGGER_TYPES: Final[set[str]] = {"enters", "leaves"}
 
-TRIGGER_SCHEMA = TRIGGER_BASE_SCHEMA.extend(
+TRIGGER_SCHEMA: Final = TRIGGER_BASE_SCHEMA.extend(
     {
         vol.Required(CONF_ENTITY_ID): cv.entity_id,
         vol.Required(CONF_TYPE): vol.In(TRIGGER_TYPES),
@@ -88,7 +90,9 @@ async def async_attach_trigger(
     )
 
 
-async def async_get_trigger_capabilities(hass: HomeAssistant, config: ConfigType):
+async def async_get_trigger_capabilities(
+    hass: HomeAssistant, config: ConfigType
+) -> dict[str, vol.Schema]:
     """List trigger capabilities."""
     zones = {
         ent.entity_id: ent.name
diff --git a/homeassistant/components/device_tracker/legacy.py b/homeassistant/components/device_tracker/legacy.py
index bdef9b83c94..333549e82e0 100644
--- a/homeassistant/components/device_tracker/legacy.py
+++ b/homeassistant/components/device_tracker/legacy.py
@@ -2,7 +2,7 @@
 from __future__ import annotations
 
 import asyncio
-from collections.abc import Sequence
+from collections.abc import Coroutine, Sequence
 from datetime import timedelta
 import hashlib
 from types import ModuleType
@@ -28,7 +28,7 @@ from homeassistant.const import (
     STATE_HOME,
     STATE_NOT_HOME,
 )
-from homeassistant.core import HomeAssistant, callback
+from homeassistant.core import HomeAssistant, ServiceCall, callback
 from homeassistant.exceptions import HomeAssistantError
 from homeassistant.helpers import config_per_platform, discovery
 import homeassistant.helpers.config_validation as cv
@@ -38,7 +38,7 @@ from homeassistant.helpers.event import (
     async_track_utc_time_change,
 )
 from homeassistant.helpers.restore_state import RestoreEntity
-from homeassistant.helpers.typing import ConfigType, GPSType
+from homeassistant.helpers.typing import ConfigType, GPSType, StateType
 from homeassistant.setup import async_prepare_setup_platform, async_start_setup
 from homeassistant.util import dt as dt_util
 from homeassistant.util.yaml import dump
@@ -69,9 +69,9 @@ from .const import (
     SOURCE_TYPE_ROUTER,
 )
 
-SERVICE_SEE = "see"
+SERVICE_SEE: Final = "see"
 
-SOURCE_TYPES = (
+SOURCE_TYPES: Final[tuple[str, ...]] = (
     SOURCE_TYPE_GPS,
     SOURCE_TYPE_ROUTER,
     SOURCE_TYPE_BLUETOOTH,
@@ -92,9 +92,11 @@ PLATFORM_SCHEMA: Final = cv.PLATFORM_SCHEMA.extend(
         vol.Optional(CONF_NEW_DEVICE_DEFAULTS, default={}): NEW_DEVICE_DEFAULTS_SCHEMA,
     }
 )
-PLATFORM_SCHEMA_BASE = cv.PLATFORM_SCHEMA_BASE.extend(PLATFORM_SCHEMA.schema)
+PLATFORM_SCHEMA_BASE: Final[vol.Schema] = cv.PLATFORM_SCHEMA_BASE.extend(
+    PLATFORM_SCHEMA.schema
+)
 
-SERVICE_SEE_PAYLOAD_SCHEMA = vol.Schema(
+SERVICE_SEE_PAYLOAD_SCHEMA: Final[vol.Schema] = vol.Schema(
     vol.All(
         cv.has_at_least_one_key(ATTR_MAC, ATTR_DEV_ID),
         {
@@ -115,23 +117,23 @@ SERVICE_SEE_PAYLOAD_SCHEMA = vol.Schema(
     )
 )
 
-YAML_DEVICES = "known_devices.yaml"
-EVENT_NEW_DEVICE = "device_tracker_new_device"
+YAML_DEVICES: Final = "known_devices.yaml"
+EVENT_NEW_DEVICE: Final = "device_tracker_new_device"
 
 
 def see(
     hass: HomeAssistant,
-    mac: str = None,
-    dev_id: str = None,
-    host_name: str = None,
-    location_name: str = None,
-    gps: GPSType = None,
-    gps_accuracy=None,
-    battery: int = None,
-    attributes: dict = None,
-):
+    mac: str | None = None,
+    dev_id: str | None = None,
+    host_name: str | None = None,
+    location_name: str | None = None,
+    gps: GPSType | None = None,
+    gps_accuracy: int | None = None,
+    battery: int | None = None,
+    attributes: dict | None = None,
+) -> None:
     """Call service to notify you see device."""
-    data = {
+    data: dict[str, Any] = {
         key: value
         for key, value in (
             (ATTR_MAC, mac),
@@ -144,7 +146,7 @@ def see(
         )
         if value is not None
     }
-    if attributes:
+    if attributes is not None:
         data[ATTR_ATTRIBUTES] = attributes
     hass.services.call(DOMAIN, SERVICE_SEE, data)
 
@@ -163,7 +165,9 @@ async def async_setup_integration(hass: HomeAssistant, config: ConfigType) -> No
     if setup_tasks:
         await asyncio.wait(setup_tasks)
 
-    async def async_platform_discovered(p_type, info):
+    async def async_platform_discovered(
+        p_type: str, info: dict[str, Any] | None
+    ) -> None:
         """Load a platform."""
         platform = await async_create_platform_type(hass, config, p_type, {})
 
@@ -179,7 +183,7 @@ async def async_setup_integration(hass: HomeAssistant, config: ConfigType) -> No
         hass, tracker.async_update_stale, second=range(0, 60, 5)
     )
 
-    async def async_see_service(call):
+    async def async_see_service(call: ServiceCall) -> None:
         """Service to see a device."""
         # Temp workaround for iOS, introduced in 0.65
         data = dict(call.data)
@@ -199,7 +203,7 @@ async def async_setup_integration(hass: HomeAssistant, config: ConfigType) -> No
 class DeviceTrackerPlatform:
     """Class to hold platform information."""
 
-    LEGACY_SETUP = (
+    LEGACY_SETUP: Final[tuple[str, ...]] = (
         "async_get_scanner",
         "get_scanner",
         "async_setup_scanner",
@@ -211,17 +215,22 @@ class DeviceTrackerPlatform:
     config: dict = attr.ib()
 
     @property
-    def type(self):
+    def type(self) -> str | None:
         """Return platform type."""
-        for methods, platform_type in ((self.LEGACY_SETUP, PLATFORM_TYPE_LEGACY),):
-            for meth in methods:
-                if hasattr(self.platform, meth):
-                    return platform_type
-
+        methods, platform_type = self.LEGACY_SETUP, PLATFORM_TYPE_LEGACY
+        for method in methods:
+            if hasattr(self.platform, method):
+                return platform_type
         return None
 
-    async def async_setup_legacy(self, hass, tracker, discovery_info=None):
+    async def async_setup_legacy(
+        self,
+        hass: HomeAssistant,
+        tracker: DeviceTracker,
+        discovery_info: dict[str, Any] | None = None,
+    ) -> None:
         """Set up a legacy platform."""
+        assert self.type == PLATFORM_TYPE_LEGACY
         full_name = f"{DOMAIN}.{self.name}"
         LOGGER.info("Setting up %s", full_name)
         with async_start_setup(hass, [full_name]):
@@ -229,20 +238,22 @@ class DeviceTrackerPlatform:
                 scanner = None
                 setup = None
                 if hasattr(self.platform, "async_get_scanner"):
-                    scanner = await self.platform.async_get_scanner(
+                    scanner = await self.platform.async_get_scanner(  # type: ignore[attr-defined]
                         hass, {DOMAIN: self.config}
                     )
                 elif hasattr(self.platform, "get_scanner"):
                     scanner = await hass.async_add_executor_job(
-                        self.platform.get_scanner, hass, {DOMAIN: self.config}
+                        self.platform.get_scanner,  # type: ignore[attr-defined]
+                        hass,
+                        {DOMAIN: self.config},
                     )
                 elif hasattr(self.platform, "async_setup_scanner"):
-                    setup = await self.platform.async_setup_scanner(
+                    setup = await self.platform.async_setup_scanner(  # type: ignore[attr-defined]
                         hass, self.config, tracker.async_see, discovery_info
                     )
                 elif hasattr(self.platform, "setup_scanner"):
                     setup = await hass.async_add_executor_job(
-                        self.platform.setup_scanner,
+                        self.platform.setup_scanner,  # type: ignore[attr-defined]
                         hass,
                         self.config,
                         tracker.see,
@@ -251,12 +262,12 @@ class DeviceTrackerPlatform:
                 else:
                     raise HomeAssistantError("Invalid legacy device_tracker platform.")
 
-                if scanner:
+                if scanner is not None:
                     async_setup_scanner_platform(
                         hass, self.config, scanner, tracker.async_see, self.type
                     )
 
-                if not setup and not scanner:
+                if setup is None and scanner is None:
                     LOGGER.error(
                         "Error setting up platform %s %s", self.type, self.name
                     )
@@ -270,9 +281,11 @@ class DeviceTrackerPlatform:
                 )
 
 
-async def async_extract_config(hass, config):
+async def async_extract_config(
+    hass: HomeAssistant, config: ConfigType
+) -> list[DeviceTrackerPlatform]:
     """Extract device tracker config and split between legacy and modern."""
-    legacy = []
+    legacy: list[DeviceTrackerPlatform] = []
 
     for platform in await asyncio.gather(
         *(
@@ -294,7 +307,7 @@ async def async_extract_config(hass, config):
 
 
 async def async_create_platform_type(
-    hass, config, p_type, p_config
+    hass: HomeAssistant, config: ConfigType, p_type: str, p_config: dict
 ) -> DeviceTrackerPlatform | None:
     """Determine type of platform."""
     platform = await async_prepare_setup_platform(hass, config, DOMAIN, p_type)
@@ -310,9 +323,9 @@ def async_setup_scanner_platform(
     hass: HomeAssistant,
     config: ConfigType,
     scanner: DeviceScanner,
-    async_see_device: Callable,
+    async_see_device: Callable[..., Coroutine[None, None, None]],
     platform: str,
-):
+) -> None:
     """Set up the connect scanner-based platform to device tracker.
 
     This method must be run in the event loop.
@@ -324,7 +337,7 @@ def async_setup_scanner_platform(
     # Initial scan of each mac we also tell about host name for config
     seen: Any = set()
 
-    async def async_device_tracker_scan(now: dt_util.dt.datetime | None):
+    async def async_device_tracker_scan(now: dt_util.dt.datetime | None) -> None:
         """Handle interval matches."""
         if update_lock.locked():
             LOGGER.warning(
@@ -350,7 +363,7 @@ def async_setup_scanner_platform(
             except NotImplementedError:
                 extra_attributes = {}
 
-            kwargs = {
+            kwargs: dict[str, Any] = {
                 "mac": mac,
                 "host_name": host_name,
                 "source_type": SOURCE_TYPE_ROUTER,
@@ -361,7 +374,7 @@ def async_setup_scanner_platform(
             }
 
             zone_home = hass.states.get(hass.components.zone.ENTITY_ID_HOME)
-            if zone_home:
+            if zone_home is not None:
                 kwargs["gps"] = [
                     zone_home.attributes[ATTR_LATITUDE],
                     zone_home.attributes[ATTR_LONGITUDE],
@@ -374,7 +387,7 @@ def async_setup_scanner_platform(
     hass.async_create_task(async_device_tracker_scan(None))
 
 
-async def get_tracker(hass, config):
+async def get_tracker(hass: HomeAssistant, config: ConfigType) -> DeviceTracker:
     """Create a tracker."""
     yaml_path = hass.config.path(YAML_DEVICES)
 
@@ -400,12 +413,12 @@ class DeviceTracker:
         hass: HomeAssistant,
         consider_home: timedelta,
         track_new: bool,
-        defaults: dict,
-        devices: Sequence,
+        defaults: dict[str, Any],
+        devices: Sequence[Device],
     ) -> None:
         """Initialize a device tracker."""
         self.hass = hass
-        self.devices = {dev.dev_id: dev for dev in devices}
+        self.devices: dict[str, Device] = {dev.dev_id: dev for dev in devices}
         self.mac_to_dev = {dev.mac: dev for dev in devices if dev.mac}
         self.consider_home = consider_home
         self.track_new = (
@@ -436,7 +449,7 @@ class DeviceTracker:
         picture: str | None = None,
         icon: str | None = None,
         consider_home: timedelta | None = None,
-    ):
+    ) -> None:
         """Notify the device tracker that you see a device."""
         self.hass.create_task(
             self.async_see(
@@ -556,7 +569,7 @@ class DeviceTracker:
             )
         )
 
-    async def async_update_config(self, path, dev_id, device):
+    async def async_update_config(self, path: str, dev_id: str, device: Device) -> None:
         """Add device to YAML configuration file.
 
         This method is a coroutine.
@@ -567,7 +580,7 @@ class DeviceTracker:
             )
 
     @callback
-    def async_update_stale(self, now: dt_util.dt.datetime):
+    def async_update_stale(self, now: dt_util.dt.datetime) -> None:
         """Update stale devices.
 
         This method must be run in the event loop.
@@ -576,18 +589,18 @@ class DeviceTracker:
             if (device.track and device.last_update_home) and device.stale(now):
                 self.hass.async_create_task(device.async_update_ha_state(True))
 
-    async def async_setup_tracked_device(self):
+    async def async_setup_tracked_device(self) -> None:
         """Set up all not exists tracked devices.
 
         This method is a coroutine.
         """
 
-        async def async_init_single_device(dev):
+        async def async_init_single_device(dev: Device) -> None:
             """Init a single device_tracker entity."""
             await dev.async_added_to_hass()
             dev.async_write_ha_state()
 
-        tasks = []
+        tasks: list[asyncio.Task] = []
         for device in self.devices.values():
             if device.track and not device.last_seen:
                 tasks.append(
@@ -610,8 +623,8 @@ class Device(RestoreEntity):
     attributes: dict | None = None
 
     # Track if the last update of this device was HOME.
-    last_update_home = False
-    _state = STATE_NOT_HOME
+    last_update_home: bool = False
+    _state: str = STATE_NOT_HOME
 
     def __init__(
         self,
@@ -644,6 +657,7 @@ class Device(RestoreEntity):
         self.config_name = name
 
         # Configured picture
+        self.config_picture: str | None
         if gravatar is not None:
             self.config_picture = get_gravatar_for_email(gravatar)
         else:
@@ -656,32 +670,32 @@ class Device(RestoreEntity):
         self._attributes: dict[str, Any] = {}
 
     @property
-    def name(self):
+    def name(self) -> str:
         """Return the name of the entity."""
         return self.config_name or self.host_name or self.dev_id or DEVICE_DEFAULT_NAME
 
     @property
-    def state(self):
+    def state(self) -> str:
         """Return the state of the device."""
         return self._state
 
     @property
-    def entity_picture(self):
+    def entity_picture(self) -> str | None:
         """Return the picture of the device."""
         return self.config_picture
 
     @final
     @property
-    def state_attributes(self):
+    def state_attributes(self) -> dict[str, StateType]:
         """Return the device state attributes."""
-        attributes = {ATTR_SOURCE_TYPE: self.source_type}
+        attributes: dict[str, StateType] = {ATTR_SOURCE_TYPE: self.source_type}
 
-        if self.gps:
+        if self.gps is not None:
             attributes[ATTR_LATITUDE] = self.gps[0]
             attributes[ATTR_LONGITUDE] = self.gps[1]
             attributes[ATTR_GPS_ACCURACY] = self.gps_accuracy
 
-        if self.battery:
+        if self.battery is not None:
             attributes[ATTR_BATTERY] = self.battery
 
         return attributes
@@ -742,13 +756,13 @@ class Device(RestoreEntity):
             or (now or dt_util.utcnow()) - self.last_seen > self.consider_home
         )
 
-    def mark_stale(self):
+    def mark_stale(self) -> None:
         """Mark the device state as stale."""
         self._state = STATE_NOT_HOME
         self.gps = None
         self.last_update_home = False
 
-    async def async_update(self):
+    async def async_update(self) -> None:
         """Update state of entity.
 
         This method is a coroutine.
@@ -773,7 +787,7 @@ class Device(RestoreEntity):
             self._state = STATE_HOME
             self.last_update_home = True
 
-    async def async_added_to_hass(self):
+    async def async_added_to_hass(self) -> None:
         """Add an entity."""
         await super().async_added_to_hass()
         state = await self.async_get_last_state()
@@ -807,7 +821,7 @@ class DeviceScanner:
         """Scan for devices."""
         raise NotImplementedError()
 
-    async def async_scan_devices(self) -> Any:
+    async def async_scan_devices(self) -> list[str]:
         """Scan for devices."""
         assert (
             self.hass is not None
@@ -829,7 +843,7 @@ class DeviceScanner:
         """Get the extra attributes of a device."""
         raise NotImplementedError()
 
-    async def async_get_extra_attributes(self, device: str) -> Any:
+    async def async_get_extra_attributes(self, device: str) -> dict:
         """Get the extra attributes of a device."""
         assert (
             self.hass is not None
@@ -837,7 +851,9 @@ class DeviceScanner:
         return await self.hass.async_add_executor_job(self.get_extra_attributes, device)
 
 
-async def async_load_config(path: str, hass: HomeAssistant, consider_home: timedelta):
+async def async_load_config(
+    path: str, hass: HomeAssistant, consider_home: timedelta
+) -> list[Device]:
     """Load devices from YAML configuration file.
 
     This method is a coroutine.
@@ -857,7 +873,7 @@ async def async_load_config(path: str, hass: HomeAssistant, consider_home: timed
             ),
         }
     )
-    result = []
+    result: list[Device] = []
     try:
         devices = await hass.async_add_executor_job(load_yaml_config_file, path)
     except HomeAssistantError as err:
@@ -880,7 +896,7 @@ async def async_load_config(path: str, hass: HomeAssistant, consider_home: timed
     return result
 
 
-def update_config(path: str, dev_id: str, device: Device):
+def update_config(path: str, dev_id: str, device: Device) -> None:
     """Add device to YAML configuration file."""
     with open(path, "a") as out:
         device_config = {
@@ -896,7 +912,7 @@ def update_config(path: str, dev_id: str, device: Device):
         out.write(dump(device_config))
 
 
-def get_gravatar_for_email(email: str):
+def get_gravatar_for_email(email: str) -> str:
     """Return an 80px Gravatar for the given email address.
 
     Async friendly.
diff --git a/mypy.ini b/mypy.ini
index ae8d4d7fa63..452a07afbb9 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -242,6 +242,17 @@ no_implicit_optional = true
 warn_return_any = true
 warn_unreachable = true
 
+[mypy-homeassistant.components.device_tracker.*]
+check_untyped_defs = true
+disallow_incomplete_defs = true
+disallow_subclassing_any = true
+disallow_untyped_calls = true
+disallow_untyped_decorators = true
+disallow_untyped_defs = true
+no_implicit_optional = true
+warn_return_any = true
+warn_unreachable = true
+
 [mypy-homeassistant.components.elgato.*]
 check_untyped_defs = true
 disallow_incomplete_defs = true