diff --git a/homeassistant/components/demo/humidifier.py b/homeassistant/components/demo/humidifier.py
index 2bdbd22eef8..7f34c23751b 100644
--- a/homeassistant/components/demo/humidifier.py
+++ b/homeassistant/components/demo/humidifier.py
@@ -28,10 +28,11 @@ async def async_setup_entry(
             DemoHumidifier(
                 name="Humidifier",
                 mode=None,
-                target_humidity=68,
+                target_humidity=65,
                 current_humidity=45,
                 action=HumidifierAction.HUMIDIFYING,
                 device_class=HumidifierDeviceClass.HUMIDIFIER,
+                target_humidity_step=5,
             ),
             DemoHumidifier(
                 name="Dehumidifier",
@@ -66,6 +67,7 @@ class DemoHumidifier(HumidifierEntity):
         is_on: bool = True,
         action: HumidifierAction | None = None,
         device_class: HumidifierDeviceClass | None = None,
+        target_humidity_step: float | None = None,
     ) -> None:
         """Initialize the humidifier device."""
         self._attr_name = name
@@ -79,6 +81,7 @@ class DemoHumidifier(HumidifierEntity):
         self._attr_mode = mode
         self._attr_available_modes = available_modes
         self._attr_device_class = device_class
+        self._attr_target_humidity_step = target_humidity_step
 
     async def async_turn_on(self, **kwargs: Any) -> None:
         """Turn the device on."""
diff --git a/homeassistant/components/humidifier/__init__.py b/homeassistant/components/humidifier/__init__.py
index de9384edda6..8ee4a1eaf78 100644
--- a/homeassistant/components/humidifier/__init__.py
+++ b/homeassistant/components/humidifier/__init__.py
@@ -34,6 +34,7 @@ from .const import (  # noqa: F401
     ATTR_HUMIDITY,
     ATTR_MAX_HUMIDITY,
     ATTR_MIN_HUMIDITY,
+    ATTR_TARGET_HUMIDITY_STEP,
     DEFAULT_MAX_HUMIDITY,
     DEFAULT_MIN_HUMIDITY,
     DOMAIN,
@@ -141,6 +142,7 @@ CACHED_PROPERTIES_WITH_ATTR_ = {
     "min_humidity",
     "max_humidity",
     "supported_features",
+    "target_humidity_step",
 }
 
 
@@ -148,7 +150,12 @@ class HumidifierEntity(ToggleEntity, cached_properties=CACHED_PROPERTIES_WITH_AT
     """Base class for humidifier entities."""
 
     _entity_component_unrecorded_attributes = frozenset(
-        {ATTR_MIN_HUMIDITY, ATTR_MAX_HUMIDITY, ATTR_AVAILABLE_MODES}
+        {
+            ATTR_MIN_HUMIDITY,
+            ATTR_MAX_HUMIDITY,
+            ATTR_AVAILABLE_MODES,
+            ATTR_TARGET_HUMIDITY_STEP,
+        }
     )
 
     entity_description: HumidifierEntityDescription
@@ -161,6 +168,7 @@ class HumidifierEntity(ToggleEntity, cached_properties=CACHED_PROPERTIES_WITH_AT
     _attr_mode: str | None
     _attr_supported_features: HumidifierEntityFeature = HumidifierEntityFeature(0)
     _attr_target_humidity: float | None = None
+    _attr_target_humidity_step: float | None = None
 
     @property
     def capability_attributes(self) -> dict[str, Any]:
@@ -169,6 +177,8 @@ class HumidifierEntity(ToggleEntity, cached_properties=CACHED_PROPERTIES_WITH_AT
             ATTR_MIN_HUMIDITY: self.min_humidity,
             ATTR_MAX_HUMIDITY: self.max_humidity,
         }
+        if self.target_humidity_step is not None:
+            data[ATTR_TARGET_HUMIDITY_STEP] = self.target_humidity_step
 
         if HumidifierEntityFeature.MODES in self.supported_features:
             data[ATTR_AVAILABLE_MODES] = self.available_modes
@@ -251,6 +261,11 @@ class HumidifierEntity(ToggleEntity, cached_properties=CACHED_PROPERTIES_WITH_AT
         """Set new mode."""
         await self.hass.async_add_executor_job(self.set_mode, mode)
 
+    @cached_property
+    def target_humidity_step(self) -> float | None:
+        """Return the supported step of humidity."""
+        return self._attr_target_humidity_step
+
     @cached_property
     def min_humidity(self) -> float:
         """Return the minimum humidity."""
diff --git a/homeassistant/components/humidifier/const.py b/homeassistant/components/humidifier/const.py
index ceef0c5a890..494ff7e5409 100644
--- a/homeassistant/components/humidifier/const.py
+++ b/homeassistant/components/humidifier/const.py
@@ -28,6 +28,7 @@ ATTR_CURRENT_HUMIDITY = "current_humidity"
 ATTR_HUMIDITY = "humidity"
 ATTR_MAX_HUMIDITY = "max_humidity"
 ATTR_MIN_HUMIDITY = "min_humidity"
+ATTR_TARGET_HUMIDITY_STEP = "target_humidity_step"
 
 DEFAULT_MIN_HUMIDITY = 0
 DEFAULT_MAX_HUMIDITY = 100
diff --git a/tests/components/google_assistant/test_google_assistant.py b/tests/components/google_assistant/test_google_assistant.py
index 26541d33613..3a7efe2b9b6 100644
--- a/tests/components/google_assistant/test_google_assistant.py
+++ b/tests/components/google_assistant/test_google_assistant.py
@@ -354,7 +354,7 @@ async def test_query_humidifier_request(
     assert devices["humidifier.humidifier"] == {
         "on": True,
         "online": True,
-        "humiditySetpointPercent": 68,
+        "humiditySetpointPercent": 65,
         "humidityAmbientPercent": 45,
     }
     assert devices["humidifier.dehumidifier"] == {
diff --git a/tests/components/humidifier/test_recorder.py b/tests/components/humidifier/test_recorder.py
index 733f505d0ab..155ae2874f5 100644
--- a/tests/components/humidifier/test_recorder.py
+++ b/tests/components/humidifier/test_recorder.py
@@ -9,6 +9,7 @@ from homeassistant.components.humidifier import (
     ATTR_AVAILABLE_MODES,
     ATTR_MAX_HUMIDITY,
     ATTR_MIN_HUMIDITY,
+    ATTR_TARGET_HUMIDITY_STEP,
 )
 from homeassistant.components.recorder import Recorder
 from homeassistant.components.recorder.history import get_significant_states
@@ -46,3 +47,4 @@ async def test_exclude_attributes(recorder_mock: Recorder, hass: HomeAssistant)
         assert ATTR_MAX_HUMIDITY not in state.attributes
         assert ATTR_AVAILABLE_MODES not in state.attributes
         assert ATTR_FRIENDLY_NAME in state.attributes
+        assert ATTR_TARGET_HUMIDITY_STEP not in state.attributes