diff --git a/homeassistant/components/demo/humidifier.py b/homeassistant/components/demo/humidifier.py
index 7ee5c0fc6ef..9065c5971fb 100644
--- a/homeassistant/components/demo/humidifier.py
+++ b/homeassistant/components/demo/humidifier.py
@@ -1,12 +1,8 @@
 """Demo platform that offers a fake humidifier device."""
 from __future__ import annotations
 
-from homeassistant.components.humidifier import HumidifierEntity
-from homeassistant.components.humidifier.const import (
-    DEVICE_CLASS_DEHUMIDIFIER,
-    DEVICE_CLASS_HUMIDIFIER,
-    SUPPORT_MODES,
-)
+from homeassistant.components.humidifier import HumidifierDeviceClass, HumidifierEntity
+from homeassistant.components.humidifier.const import SUPPORT_MODES
 
 SUPPORT_FLAGS = 0
 
@@ -19,13 +15,13 @@ async def async_setup_platform(hass, config, async_add_entities, discovery_info=
                 name="Humidifier",
                 mode=None,
                 target_humidity=68,
-                device_class=DEVICE_CLASS_HUMIDIFIER,
+                device_class=HumidifierDeviceClass.HUMIDIFIER,
             ),
             DemoHumidifier(
                 name="Dehumidifier",
                 mode=None,
                 target_humidity=54,
-                device_class=DEVICE_CLASS_DEHUMIDIFIER,
+                device_class=HumidifierDeviceClass.DEHUMIDIFIER,
             ),
             DemoHumidifier(
                 name="Hygrostat",
@@ -54,7 +50,7 @@ class DemoHumidifier(HumidifierEntity):
         target_humidity: int,
         available_modes: list[str] | None = None,
         is_on: bool = True,
-        device_class: str | None = None,
+        device_class: HumidifierDeviceClass | None = None,
     ) -> None:
         """Initialize the humidifier device."""
         self._attr_name = name
diff --git a/homeassistant/components/humidifier/__init__.py b/homeassistant/components/humidifier/__init__.py
index 48a71662be1..e6ec8dc72f2 100644
--- a/homeassistant/components/humidifier/__init__.py
+++ b/homeassistant/components/humidifier/__init__.py
@@ -26,8 +26,9 @@ from homeassistant.helpers.entity import ToggleEntity, ToggleEntityDescription
 from homeassistant.helpers.entity_component import EntityComponent
 from homeassistant.helpers.typing import ConfigType
 from homeassistant.loader import bind_hass
+from homeassistant.util.enum import StrEnum
 
-from .const import (
+from .const import (  # noqa: F401
     ATTR_AVAILABLE_MODES,
     ATTR_HUMIDITY,
     ATTR_MAX_HUMIDITY,
@@ -49,9 +50,19 @@ SCAN_INTERVAL = timedelta(seconds=60)
 
 ENTITY_ID_FORMAT = DOMAIN + ".{}"
 
-DEVICE_CLASSES = [DEVICE_CLASS_HUMIDIFIER, DEVICE_CLASS_DEHUMIDIFIER]
 
-DEVICE_CLASSES_SCHEMA = vol.All(vol.Lower, vol.In(DEVICE_CLASSES))
+class HumidifierDeviceClass(StrEnum):
+    """Device class for humidifiers."""
+
+    HUMIDIFIER = "humidifier"
+    DEHUMIDIFIER = "dehumidifier"
+
+
+DEVICE_CLASSES_SCHEMA = vol.All(vol.Lower, vol.Coerce(HumidifierDeviceClass))
+
+# DEVICE_CLASSES below is deprecated as of 2021.12
+# use the HumidifierDeviceClass enum instead.
+DEVICE_CLASSES = [cls.value for cls in HumidifierDeviceClass]
 
 
 @bind_hass
@@ -108,12 +119,15 @@ async def async_unload_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
 class HumidifierEntityDescription(ToggleEntityDescription):
     """A class that describes humidifier entities."""
 
+    device_class: HumidifierDeviceClass | str | None = None
+
 
 class HumidifierEntity(ToggleEntity):
     """Base class for humidifier entities."""
 
     entity_description: HumidifierEntityDescription
     _attr_available_modes: list[str] | None
+    _attr_device_class: HumidifierDeviceClass | str | None
     _attr_max_humidity: int = DEFAULT_MAX_HUMIDITY
     _attr_min_humidity: int = DEFAULT_MIN_HUMIDITY
     _attr_mode: str | None
@@ -133,6 +147,15 @@ class HumidifierEntity(ToggleEntity):
 
         return data
 
+    @property
+    def device_class(self) -> HumidifierDeviceClass | str | None:
+        """Return the class of this entity."""
+        if hasattr(self, "_attr_device_class"):
+            return self._attr_device_class
+        if hasattr(self, "entity_description"):
+            return self.entity_description.device_class
+        return None
+
     @final
     @property
     def state_attributes(self) -> dict[str, Any]:
diff --git a/homeassistant/components/humidifier/const.py b/homeassistant/components/humidifier/const.py
index c2508770187..a3df2756af9 100644
--- a/homeassistant/components/humidifier/const.py
+++ b/homeassistant/components/humidifier/const.py
@@ -19,6 +19,8 @@ DEFAULT_MAX_HUMIDITY = 100
 
 DOMAIN = "humidifier"
 
+# DEVICE_CLASS_* below are deprecated as of 2021.12
+# use the HumidifierDeviceClass enum instead.
 DEVICE_CLASS_HUMIDIFIER = "humidifier"
 DEVICE_CLASS_DEHUMIDIFIER = "dehumidifier"