diff --git a/homeassistant/components/google_assistant/const.py b/homeassistant/components/google_assistant/const.py
index 03253e244fe..5209f6040c1 100644
--- a/homeassistant/components/google_assistant/const.py
+++ b/homeassistant/components/google_assistant/const.py
@@ -135,6 +135,7 @@ DEVICE_CLASS_TO_GOOGLE_TYPES = {
     (media_player.DOMAIN, media_player.DEVICE_CLASS_TV): TYPE_TV,
     (media_player.DOMAIN, media_player.DEVICE_CLASS_SPEAKER): TYPE_SPEAKER,
     (sensor.DOMAIN, sensor.DEVICE_CLASS_TEMPERATURE): TYPE_SENSOR,
+    (sensor.DOMAIN, sensor.DEVICE_CLASS_HUMIDITY): TYPE_SENSOR,
 }
 
 CHALLENGE_ACK_NEEDED = "ackNeeded"
diff --git a/homeassistant/components/google_assistant/trait.py b/homeassistant/components/google_assistant/trait.py
index 6b5530ab2ce..5b089459d83 100644
--- a/homeassistant/components/google_assistant/trait.py
+++ b/homeassistant/components/google_assistant/trait.py
@@ -80,6 +80,7 @@ TRAIT_MODES = PREFIX_TRAITS + "Modes"
 TRAIT_OPENCLOSE = PREFIX_TRAITS + "OpenClose"
 TRAIT_VOLUME = PREFIX_TRAITS + "Volume"
 TRAIT_ARMDISARM = PREFIX_TRAITS + "ArmDisarm"
+TRAIT_HUMIDITY_SETTING = PREFIX_TRAITS + "HumiditySetting"
 
 PREFIX_COMMANDS = "action.devices.commands."
 COMMAND_ONOFF = PREFIX_COMMANDS + "OnOff"
@@ -849,6 +850,56 @@ class TemperatureSettingTrait(_Trait):
             )
 
 
+@register_trait
+class HumiditySettingTrait(_Trait):
+    """Trait to offer humidity setting functionality.
+
+    https://developers.google.com/actions/smarthome/traits/humiditysetting
+    """
+
+    name = TRAIT_HUMIDITY_SETTING
+    commands = []
+
+    @staticmethod
+    def supported(domain, features, device_class):
+        """Test if state is supported."""
+        return domain == sensor.DOMAIN and device_class == sensor.DEVICE_CLASS_HUMIDITY
+
+    def sync_attributes(self):
+        """Return humidity attributes for a sync request."""
+        response = {}
+        attrs = self.state.attributes
+        domain = self.state.domain
+        if domain == sensor.DOMAIN:
+            device_class = attrs.get(ATTR_DEVICE_CLASS)
+            if device_class == sensor.DEVICE_CLASS_HUMIDITY:
+                response["queryOnlyHumiditySetting"] = True
+
+        return response
+
+    def query_attributes(self):
+        """Return humidity query attributes."""
+        response = {}
+        attrs = self.state.attributes
+        domain = self.state.domain
+        if domain == sensor.DOMAIN:
+            device_class = attrs.get(ATTR_DEVICE_CLASS)
+            if device_class == sensor.DEVICE_CLASS_HUMIDITY:
+                current_humidity = self.state.state
+                if current_humidity is not None:
+                    response["humidityAmbientPercent"] = round(float(current_humidity))
+
+        return response
+
+    async def execute(self, command, data, params, challenge):
+        """Execute a humidity command."""
+        domain = self.state.domain
+        if domain == sensor.DOMAIN:
+            raise SmartHomeError(
+                ERR_NOT_SUPPORTED, "Execute is not supported by sensor"
+            )
+
+
 @register_trait
 class LockUnlockTrait(_Trait):
     """Trait to lock or unlock a lock.
diff --git a/tests/components/google_assistant/test_trait.py b/tests/components/google_assistant/test_trait.py
index d6ec24a7867..6d24aa0942f 100644
--- a/tests/components/google_assistant/test_trait.py
+++ b/tests/components/google_assistant/test_trait.py
@@ -1629,3 +1629,29 @@ async def test_temperature_setting_sensor(hass):
 
     assert trt.query_attributes() == {"thermostatTemperatureAmbient": 21.1}
     hass.config.units.temperature_unit = TEMP_CELSIUS
+
+
+async def test_humidity_setting_sensor(hass):
+    """Test HumiditySetting trait support for humidity sensor."""
+    assert (
+        helpers.get_google_type(sensor.DOMAIN, sensor.DEVICE_CLASS_HUMIDITY) is not None
+    )
+    assert not trait.HumiditySettingTrait.supported(
+        sensor.DOMAIN, 0, sensor.DEVICE_CLASS_TEMPERATURE
+    )
+    assert trait.HumiditySettingTrait.supported(
+        sensor.DOMAIN, 0, sensor.DEVICE_CLASS_HUMIDITY
+    )
+
+    trt = trait.HumiditySettingTrait(
+        hass,
+        State("sensor.test", "70", {ATTR_DEVICE_CLASS: sensor.DEVICE_CLASS_HUMIDITY}),
+        BASIC_CONFIG,
+    )
+
+    assert trt.sync_attributes() == {"queryOnlyHumiditySetting": True}
+    assert trt.query_attributes() == {"humidityAmbientPercent": 70}
+
+    with pytest.raises(helpers.SmartHomeError) as err:
+        await trt.execute(trait.COMMAND_ONOFF, BASIC_DATA, {"on": False}, {})
+    assert err.value.code == const.ERR_NOT_SUPPORTED