diff --git a/.strict-typing b/.strict-typing
index 77f7b6f50c2..1832a83641a 100644
--- a/.strict-typing
+++ b/.strict-typing
@@ -87,6 +87,7 @@ homeassistant.components.emulated_hue.*
 homeassistant.components.esphome.*
 homeassistant.components.energy.*
 homeassistant.components.evil_genius_labs.*
+homeassistant.components.fan.*
 homeassistant.components.fastdotcom.*
 homeassistant.components.filesize.*
 homeassistant.components.fitbit.*
diff --git a/homeassistant/components/fan/__init__.py b/homeassistant/components/fan/__init__.py
index 5eb3bedabd5..8f6585f6535 100644
--- a/homeassistant/components/fan/__init__.py
+++ b/homeassistant/components/fan/__init__.py
@@ -7,7 +7,7 @@ from enum import IntEnum
 import functools as ft
 import logging
 import math
-from typing import final
+from typing import Any, final
 
 import voluptuous as vol
 
@@ -80,9 +80,11 @@ class NotValidPresetModeError(ValueError):
 
 
 @bind_hass
-def is_on(hass, entity_id: str) -> bool:
+def is_on(hass: HomeAssistant, entity_id: str) -> bool:
     """Return if the fans are on based on the statemachine."""
-    return hass.states.get(entity_id).state == STATE_ON
+    entity = hass.states.get(entity_id)
+    assert entity
+    return entity.state == STATE_ON
 
 
 async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
@@ -235,7 +237,7 @@ class FanEntity(ToggleEntity):
         """Set new preset mode."""
         await self.hass.async_add_executor_job(self.set_preset_mode, preset_mode)
 
-    def _valid_preset_mode_or_raise(self, preset_mode):
+    def _valid_preset_mode_or_raise(self, preset_mode: str) -> None:
         """Raise NotValidPresetModeError on invalid preset_mode."""
         preset_modes = self.preset_modes
         if not preset_modes or preset_mode not in preset_modes:
@@ -247,7 +249,7 @@ class FanEntity(ToggleEntity):
         """Set the direction of the fan."""
         raise NotImplementedError()
 
-    async def async_set_direction(self, direction: str):
+    async def async_set_direction(self, direction: str) -> None:
         """Set the direction of the fan."""
         await self.hass.async_add_executor_job(self.set_direction, direction)
 
@@ -255,7 +257,7 @@ class FanEntity(ToggleEntity):
         self,
         percentage: int | None = None,
         preset_mode: str | None = None,
-        **kwargs,
+        **kwargs: Any,
     ) -> None:
         """Turn on the fan."""
         raise NotImplementedError()
@@ -264,7 +266,7 @@ class FanEntity(ToggleEntity):
         self,
         percentage: int | None = None,
         preset_mode: str | None = None,
-        **kwargs,
+        **kwargs: Any,
     ) -> None:
         """Turn on the fan."""
         await self.hass.async_add_executor_job(
@@ -280,12 +282,12 @@ class FanEntity(ToggleEntity):
         """Oscillate the fan."""
         raise NotImplementedError()
 
-    async def async_oscillate(self, oscillating: bool):
+    async def async_oscillate(self, oscillating: bool) -> None:
         """Oscillate the fan."""
         await self.hass.async_add_executor_job(self.oscillate, oscillating)
 
     @property
-    def is_on(self):
+    def is_on(self) -> bool | None:
         """Return true if the entity is on."""
         return (
             self.percentage is not None and self.percentage > 0
@@ -321,7 +323,7 @@ class FanEntity(ToggleEntity):
         return self._attr_oscillating
 
     @property
-    def capability_attributes(self):
+    def capability_attributes(self) -> dict[str, list[str] | None]:
         """Return capability attributes."""
         attrs = {}
 
@@ -335,7 +337,7 @@ class FanEntity(ToggleEntity):
 
     @final
     @property
-    def state_attributes(self) -> dict:
+    def state_attributes(self) -> dict[str, float | str | None]:
         """Return optional state attributes."""
         data: dict[str, float | str | None] = {}
         supported_features = self.supported_features
diff --git a/homeassistant/components/vallox/fan.py b/homeassistant/components/vallox/fan.py
index 6872acbb5b7..4ba7d2d88fd 100644
--- a/homeassistant/components/vallox/fan.py
+++ b/homeassistant/components/vallox/fan.py
@@ -132,7 +132,7 @@ class ValloxFan(ValloxEntity, FanEntity):
         Returns true if the mode has been changed, false otherwise.
         """
         try:
-            self._valid_preset_mode_or_raise(preset_mode)  # type: ignore[no-untyped-call]
+            self._valid_preset_mode_or_raise(preset_mode)
 
         except NotValidPresetModeError as err:
             _LOGGER.error(err)
diff --git a/mypy.ini b/mypy.ini
index 19241872474..8dca7403eff 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -720,6 +720,17 @@ no_implicit_optional = true
 warn_return_any = true
 warn_unreachable = true
 
+[mypy-homeassistant.components.fan.*]
+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.fastdotcom.*]
 check_untyped_defs = true
 disallow_incomplete_defs = true