diff --git a/homeassistant/components/hassio/__init__.py b/homeassistant/components/hassio/__init__.py
index 69c53225d49..49ea884418f 100644
--- a/homeassistant/components/hassio/__init__.py
+++ b/homeassistant/components/hassio/__init__.py
@@ -127,20 +127,27 @@ MAP_SERVICE_API = {
 
 
 @bind_hass
-async def async_get_addon_info(hass: HomeAssistantType, addon_id: str) -> dict:
+async def async_get_addon_info(hass: HomeAssistantType, slug: str) -> dict:
     """Return add-on info.
 
-    The addon_id is a snakecased concatenation of the 'repository' value
-    found in the add-on info and the 'slug' value found in the add-on config.json.
-    In the add-on info the addon_id is called 'slug'.
-
     The caller of the function should handle HassioAPIError.
     """
     hassio = hass.data[DOMAIN]
-    result = await hassio.get_addon_info(addon_id)
+    result = await hassio.get_addon_info(slug)
     return result["data"]
 
 
+@bind_hass
+async def async_install_addon(hass: HomeAssistantType, slug: str) -> None:
+    """Install add-on.
+
+    The caller of the function should handle HassioAPIError.
+    """
+    hassio = hass.data[DOMAIN]
+    command = f"/addons/{slug}/install"
+    await hassio.send_command(command)
+
+
 @callback
 @bind_hass
 def get_info(hass):