diff --git a/homeassistant/components/smartthings/fan.py b/homeassistant/components/smartthings/fan.py
index 9aa467cbfa8..ef3d9702ce2 100644
--- a/homeassistant/components/smartthings/fan.py
+++ b/homeassistant/components/smartthings/fan.py
@@ -119,7 +119,7 @@ class SmartThingsFan(SmartThingsEntity, FanEntity):
     @property
     def is_on(self) -> bool:
         """Return true if fan is on."""
-        return self.get_attribute_value(Capability.SWITCH, Attribute.SWITCH)
+        return self.get_attribute_value(Capability.SWITCH, Attribute.SWITCH) == "on"
 
     @property
     def percentage(self) -> int | None:
@@ -135,6 +135,8 @@ class SmartThingsFan(SmartThingsEntity, FanEntity):
 
         Requires FanEntityFeature.PRESET_MODE.
         """
+        if not self.supports_capability(Capability.AIR_CONDITIONER_FAN_MODE):
+            return None
         return self.get_attribute_value(
             Capability.AIR_CONDITIONER_FAN_MODE, Attribute.FAN_MODE
         )
@@ -145,6 +147,8 @@ class SmartThingsFan(SmartThingsEntity, FanEntity):
 
         Requires FanEntityFeature.PRESET_MODE.
         """
+        if not self.supports_capability(Capability.AIR_CONDITIONER_FAN_MODE):
+            return None
         return self.get_attribute_value(
             Capability.AIR_CONDITIONER_FAN_MODE, Attribute.SUPPORTED_AC_FAN_MODES
         )
diff --git a/tests/components/smartthings/conftest.py b/tests/components/smartthings/conftest.py
index c9a74862187..c78b4bc05de 100644
--- a/tests/components/smartthings/conftest.py
+++ b/tests/components/smartthings/conftest.py
@@ -119,6 +119,7 @@ def mock_smartthings() -> Generator[AsyncMock]:
         "ecobee_sensor",
         "ecobee_thermostat",
         "fake_fan",
+        "generic_fan_3_speed",
     ]
 )
 def device_fixture(
diff --git a/tests/components/smartthings/fixtures/device_status/generic_fan_3_speed.json b/tests/components/smartthings/fixtures/device_status/generic_fan_3_speed.json
new file mode 100644
index 00000000000..9335bd8e042
--- /dev/null
+++ b/tests/components/smartthings/fixtures/device_status/generic_fan_3_speed.json
@@ -0,0 +1,19 @@
+{
+  "components": {
+    "main": {
+      "refresh": {},
+      "fanSpeed": {
+        "fanSpeed": {
+          "value": 0,
+          "timestamp": "2025-03-06T11:47:32.683Z"
+        }
+      },
+      "switch": {
+        "switch": {
+          "value": "off",
+          "timestamp": "2025-03-06T11:47:32.697Z"
+        }
+      }
+    }
+  }
+}
diff --git a/tests/components/smartthings/fixtures/devices/generic_fan_3_speed.json b/tests/components/smartthings/fixtures/devices/generic_fan_3_speed.json
new file mode 100644
index 00000000000..db218189c68
--- /dev/null
+++ b/tests/components/smartthings/fixtures/devices/generic_fan_3_speed.json
@@ -0,0 +1,63 @@
+{
+  "items": [
+    {
+      "deviceId": "6d95a8b7-4ee3-429a-a13a-00ec9354170c",
+      "name": "GE In-Wall Smart Dimmer",
+      "label": "Bedroom Fan",
+      "manufacturerName": "SmartThingsEdge",
+      "presentationId": "generic-fan-3-speed",
+      "deviceManufacturerCode": "0063-4944-3131",
+      "locationId": "f1313f27-6732-481d-a2a9-c7bbf900f867",
+      "ownerId": "e5216062-ac82-79b8-20db-ea65fa3d3fdd",
+      "roomId": "5f77f7cf-ece8-485e-a409-98f7b128a41a",
+      "components": [
+        {
+          "id": "main",
+          "label": "Bedroom Fan",
+          "capabilities": [
+            {
+              "id": "fanSpeed",
+              "version": 1
+            },
+            {
+              "id": "switch",
+              "version": 1
+            },
+            {
+              "id": "refresh",
+              "version": 1
+            }
+          ],
+          "categories": [
+            {
+              "name": "Fan",
+              "categoryType": "manufacturer"
+            }
+          ]
+        }
+      ],
+      "createTime": "2018-01-12T22:12:15Z",
+      "parentDeviceId": "4ceb9b86-2f0d-4e98-ba4e-3fbe705f7805",
+      "profile": {
+        "id": "9bd81754-fc81-3ed1-86c2-d1094d6cbf6d"
+      },
+      "zwave": {
+        "networkId": "02",
+        "driverId": "e7947a05-947d-4bb5-92c4-2aafaff6d69c",
+        "executingLocally": true,
+        "hubId": "4ceb9b86-2f0d-4e98-ba4e-3fbe705f7805",
+        "networkSecurityLevel": "ZWAVE_LEGACY_NON_SECURE",
+        "provisioningState": "PROVISIONED",
+        "manufacturerId": 99,
+        "productType": 18756,
+        "productId": 12593
+      },
+      "type": "ZWAVE",
+      "restrictionTier": 0,
+      "allowed": null,
+      "executionContext": "LOCAL",
+      "relationships": []
+    }
+  ],
+  "_links": {}
+}
diff --git a/tests/components/smartthings/snapshots/test_fan.ambr b/tests/components/smartthings/snapshots/test_fan.ambr
index 33caffcacc6..40ab7b12267 100644
--- a/tests/components/smartthings/snapshots/test_fan.ambr
+++ b/tests/components/smartthings/snapshots/test_fan.ambr
@@ -62,6 +62,60 @@
     'last_changed': <ANY>,
     'last_reported': <ANY>,
     'last_updated': <ANY>,
-    'state': 'on',
+    'state': 'off',
+  })
+# ---
+# name: test_all_entities[generic_fan_3_speed][fan.bedroom_fan-entry]
+  EntityRegistryEntrySnapshot({
+    'aliases': set({
+    }),
+    'area_id': None,
+    'capabilities': dict({
+      'preset_modes': None,
+    }),
+    'config_entry_id': <ANY>,
+    'config_subentry_id': <ANY>,
+    'device_class': None,
+    'device_id': <ANY>,
+    'disabled_by': None,
+    'domain': 'fan',
+    'entity_category': None,
+    'entity_id': 'fan.bedroom_fan',
+    'has_entity_name': True,
+    'hidden_by': None,
+    'icon': None,
+    'id': <ANY>,
+    'labels': set({
+    }),
+    'name': None,
+    'options': dict({
+    }),
+    'original_device_class': None,
+    'original_icon': None,
+    'original_name': None,
+    'platform': 'smartthings',
+    'previous_unique_id': None,
+    'supported_features': <FanEntityFeature: 49>,
+    'translation_key': None,
+    'unique_id': '6d95a8b7-4ee3-429a-a13a-00ec9354170c',
+    'unit_of_measurement': None,
+  })
+# ---
+# name: test_all_entities[generic_fan_3_speed][fan.bedroom_fan-state]
+  StateSnapshot({
+    'attributes': ReadOnlyDict({
+      'friendly_name': 'Bedroom Fan',
+      'percentage': 0,
+      'percentage_step': 33.333333333333336,
+      'preset_mode': None,
+      'preset_modes': None,
+      'supported_features': <FanEntityFeature: 49>,
+    }),
+    'context': <ANY>,
+    'entity_id': 'fan.bedroom_fan',
+    'last_changed': <ANY>,
+    'last_reported': <ANY>,
+    'last_updated': <ANY>,
+    'state': 'off',
   })
 # ---
diff --git a/tests/components/smartthings/snapshots/test_init.ambr b/tests/components/smartthings/snapshots/test_init.ambr
index ad7764848b4..2c09d0addaf 100644
--- a/tests/components/smartthings/snapshots/test_init.ambr
+++ b/tests/components/smartthings/snapshots/test_init.ambr
@@ -626,6 +626,39 @@
     'via_device_id': None,
   })
 # ---
+# name: test_devices[generic_fan_3_speed]
+  DeviceRegistryEntrySnapshot({
+    'area_id': None,
+    'config_entries': <ANY>,
+    'config_entries_subentries': <ANY>,
+    'configuration_url': 'https://account.smartthings.com',
+    'connections': set({
+    }),
+    'disabled_by': None,
+    'entry_type': None,
+    'hw_version': None,
+    'id': <ANY>,
+    'identifiers': set({
+      tuple(
+        'smartthings',
+        '6d95a8b7-4ee3-429a-a13a-00ec9354170c',
+      ),
+    }),
+    'is_new': False,
+    'labels': set({
+    }),
+    'manufacturer': None,
+    'model': None,
+    'model_id': None,
+    'name': 'Bedroom Fan',
+    'name_by_user': None,
+    'primary_config_entry': <ANY>,
+    'serial_number': None,
+    'suggested_area': None,
+    'sw_version': None,
+    'via_device_id': None,
+  })
+# ---
 # name: test_devices[hue_color_temperature_bulb]
   DeviceRegistryEntrySnapshot({
     'area_id': None,