diff --git a/homeassistant/components/vizio/__init__.py b/homeassistant/components/vizio/__init__.py
index 0f5b3bc967c..af9e649a8b0 100644
--- a/homeassistant/components/vizio/__init__.py
+++ b/homeassistant/components/vizio/__init__.py
@@ -67,7 +67,7 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
         CONF_APPS not in hass.data[DOMAIN]
         and entry.data[CONF_DEVICE_CLASS] == MediaPlayerDeviceClass.TV
     ):
-        store: Store = Store(hass, 1, DOMAIN)
+        store: Store[list[dict[str, Any]]] = Store(hass, 1, DOMAIN)
         coordinator = VizioAppsDataUpdateCoordinator(hass, store)
         await coordinator.async_config_entry_first_refresh()
         hass.data[DOMAIN][CONF_APPS] = coordinator
@@ -100,7 +100,7 @@ async def async_unload_entry(hass: HomeAssistant, config_entry: ConfigEntry) ->
 class VizioAppsDataUpdateCoordinator(DataUpdateCoordinator[list[dict[str, Any]]]):
     """Define an object to hold Vizio app config data."""
 
-    def __init__(self, hass: HomeAssistant, store: Store) -> None:
+    def __init__(self, hass: HomeAssistant, store: Store[list[dict[str, Any]]]) -> None:
         """Initialize."""
         super().__init__(
             hass,
diff --git a/homeassistant/components/vizio/config_flow.py b/homeassistant/components/vizio/config_flow.py
index 014cd3cab0f..792407d2545 100644
--- a/homeassistant/components/vizio/config_flow.py
+++ b/homeassistant/components/vizio/config_flow.py
@@ -188,8 +188,8 @@ class VizioConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
         """Initialize config flow."""
         self._user_schema = None
         self._must_show_form: bool | None = None
-        self._ch_type = None
-        self._pairing_token = None
+        self._ch_type: str | None = None
+        self._pairing_token: str | None = None
         self._data: dict[str, Any] | None = None
         self._apps: dict[str, list] = {}
 
@@ -208,7 +208,7 @@ class VizioConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
         self, user_input: dict[str, Any] | None = None
     ) -> FlowResult:
         """Handle a flow initialized by the user."""
-        errors = {}
+        errors: dict[str, str] = {}
 
         if user_input is not None:
             # Store current values in case setup fails and user needs to edit
@@ -294,8 +294,8 @@ class VizioConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
             if await self.hass.async_add_executor_job(
                 _host_is_same, entry.data[CONF_HOST], import_config[CONF_HOST]
             ):
-                updated_options = {}
-                updated_data = {}
+                updated_options: dict[str, Any] = {}
+                updated_data: dict[str, Any] = {}
                 remove_apps = False
 
                 if entry.data[CONF_HOST] != import_config[CONF_HOST]:
@@ -393,10 +393,10 @@ class VizioConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
         Ask user for PIN to complete pairing process.
         """
         errors: dict[str, str] = {}
+        assert self._data
 
         # Start pairing process if it hasn't already started
         if not self._ch_type and not self._pairing_token:
-            assert self._data
             dev = VizioAsync(
                 DEVICE_ID,
                 self._data[CONF_HOST],
diff --git a/homeassistant/components/vizio/media_player.py b/homeassistant/components/vizio/media_player.py
index 057fd33e8dc..e3de3caa99d 100644
--- a/homeassistant/components/vizio/media_player.py
+++ b/homeassistant/components/vizio/media_player.py
@@ -4,7 +4,7 @@ from __future__ import annotations
 from datetime import timedelta
 import logging
 
-from pyvizio import VizioAsync
+from pyvizio import AppConfig, VizioAsync
 from pyvizio.api.apps import find_app_name
 from pyvizio.const import APP_HOME, INPUT_APPS, NO_APP_RUNNING, UNKNOWN_APP
 
@@ -144,9 +144,8 @@ class VizioDevice(MediaPlayerEntity):
         self._apps_coordinator = apps_coordinator
 
         self._volume_step = config_entry.options[CONF_VOLUME_STEP]
-        self._current_input = None
-        self._current_app_config = None
-        self._attr_app_name = None
+        self._current_input: str | None = None
+        self._current_app_config: AppConfig | None = None
         self._available_inputs: list[str] = []
         self._available_apps: list[str] = []
         self._all_apps = apps_coordinator.data if apps_coordinator else None
@@ -377,7 +376,7 @@ class VizioDevice(MediaPlayerEntity):
         return self._available_inputs
 
     @property
-    def app_id(self) -> str | None:
+    def app_id(self):
         """Return the ID of the current app if it is unknown by pyvizio."""
         if self._current_app_config and self.source == UNKNOWN_APP:
             return {
@@ -388,9 +387,9 @@ class VizioDevice(MediaPlayerEntity):
 
         return None
 
-    async def async_select_sound_mode(self, sound_mode):
+    async def async_select_sound_mode(self, sound_mode: str) -> None:
         """Select sound mode."""
-        if sound_mode in self._attr_sound_mode_list:
+        if sound_mode in (self._attr_sound_mode_list or ()):
             await self._device.set_setting(
                 VIZIO_AUDIO_SETTINGS,
                 VIZIO_SOUND_MODE,