diff --git a/homeassistant/components/smartthings/const.py b/homeassistant/components/smartthings/const.py
index df14ab680550..25cd9e8305f2 100644
--- a/homeassistant/components/smartthings/const.py
+++ b/homeassistant/components/smartthings/const.py
@@ -23,6 +23,7 @@ SUPPORTED_PLATFORMS = [
     'climate',
     'fan',
     'light',
+    'lock',
     'sensor',
     'switch'
 ]
diff --git a/homeassistant/components/smartthings/lock.py b/homeassistant/components/smartthings/lock.py
new file mode 100644
index 000000000000..6dfff0bd02c6
--- /dev/null
+++ b/homeassistant/components/smartthings/lock.py
@@ -0,0 +1,73 @@
+"""
+Support for locks through the SmartThings cloud API.
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/smartthings.lock/
+"""
+from homeassistant.components.lock import LockDevice
+
+from . import SmartThingsEntity
+from .const import DATA_BROKERS, DOMAIN
+
+DEPENDENCIES = ['smartthings']
+
+ST_STATE_LOCKED = 'locked'
+ST_LOCK_ATTR_MAP = {
+    'method': 'method',
+    'codeId': 'code_id',
+    'timeout': 'timeout'
+}
+
+
+async def async_setup_platform(hass, config, async_add_entities,
+                               discovery_info=None):
+    """Platform uses config entry setup."""
+    pass
+
+
+async def async_setup_entry(hass, config_entry, async_add_entities):
+    """Add locks for a config entry."""
+    broker = hass.data[DOMAIN][DATA_BROKERS][config_entry.entry_id]
+    async_add_entities(
+        [SmartThingsLock(device) for device in broker.devices.values()
+         if is_lock(device)])
+
+
+def is_lock(device):
+    """Determine if the device supports the lock capability."""
+    from pysmartthings import Capability
+    return Capability.lock in device.capabilities
+
+
+class SmartThingsLock(SmartThingsEntity, LockDevice):
+    """Define a SmartThings lock."""
+
+    async def async_lock(self, **kwargs):
+        """Lock the device."""
+        await self._device.lock(set_status=True)
+        self.async_schedule_update_ha_state()
+
+    async def async_unlock(self, **kwargs):
+        """Unlock the device."""
+        await self._device.unlock(set_status=True)
+        self.async_schedule_update_ha_state()
+
+    @property
+    def is_locked(self):
+        """Return true if lock is locked."""
+        return self._device.status.lock == ST_STATE_LOCKED
+
+    @property
+    def device_state_attributes(self):
+        """Return device specific state attributes."""
+        from pysmartthings import Attribute
+        state_attrs = {}
+        status = self._device.status.attributes[Attribute.lock]
+        if status.value:
+            state_attrs['lock_state'] = status.value
+        if isinstance(status.data, dict):
+            for st_attr, ha_attr in ST_LOCK_ATTR_MAP.items():
+                data_val = status.data.get(st_attr)
+                if data_val is not None:
+                    state_attrs[ha_attr] = data_val
+        return state_attrs
diff --git a/tests/components/smartthings/test_lock.py b/tests/components/smartthings/test_lock.py
new file mode 100644
index 000000000000..c73f4ff549ee
--- /dev/null
+++ b/tests/components/smartthings/test_lock.py
@@ -0,0 +1,110 @@
+"""
+Test for the SmartThings lock platform.
+
+The only mocking required is of the underlying SmartThings API object so
+real HTTP calls are not initiated during testing.
+"""
+from pysmartthings import Attribute, Capability
+
+from homeassistant.components.lock import DOMAIN as LOCK_DOMAIN
+from homeassistant.components.smartthings import lock
+from homeassistant.components.smartthings.const import (
+    DOMAIN, SIGNAL_SMARTTHINGS_UPDATE)
+from homeassistant.helpers.dispatcher import async_dispatcher_send
+
+from .conftest import setup_platform
+
+
+async def test_async_setup_platform():
+    """Test setup platform does nothing (it uses config entries)."""
+    await lock.async_setup_platform(None, None, None)
+
+
+def test_is_lock(device_factory):
+    """Test locks are correctly identified."""
+    lock_device = device_factory('Lock', [Capability.lock])
+    assert lock.is_lock(lock_device)
+
+
+async def test_entity_and_device_attributes(hass, device_factory):
+    """Test the attributes of the entity are correct."""
+    # Arrange
+    device = device_factory('Lock_1', [Capability.lock],
+                            {Attribute.lock: 'unlocked'})
+    entity_registry = await hass.helpers.entity_registry.async_get_registry()
+    device_registry = await hass.helpers.device_registry.async_get_registry()
+    # Act
+    await setup_platform(hass, LOCK_DOMAIN, device)
+    # Assert
+    entry = entity_registry.async_get('lock.lock_1')
+    assert entry
+    assert entry.unique_id == device.device_id
+
+    entry = device_registry.async_get_device(
+        {(DOMAIN, device.device_id)}, [])
+    assert entry
+    assert entry.name == device.label
+    assert entry.model == device.device_type_name
+    assert entry.manufacturer == 'Unavailable'
+
+
+async def test_lock(hass, device_factory):
+    """Test the lock locks successfully."""
+    # Arrange
+    device = device_factory('Lock_1', [Capability.lock],
+                            {Attribute.lock: 'unlocked'})
+    await setup_platform(hass, LOCK_DOMAIN, device)
+    # Act
+    await hass.services.async_call(
+        LOCK_DOMAIN, 'lock', {'entity_id': 'lock.lock_1'},
+        blocking=True)
+    # Assert
+    state = hass.states.get('lock.lock_1')
+    assert state is not None
+    assert state.state == 'locked'
+
+
+async def test_unlock(hass, device_factory):
+    """Test the lock unlocks successfully."""
+    # Arrange
+    device = device_factory('Lock_1', [Capability.lock],
+                            {Attribute.lock: 'locked'})
+    await setup_platform(hass, LOCK_DOMAIN, device)
+    # Act
+    await hass.services.async_call(
+        LOCK_DOMAIN, 'unlock', {'entity_id': 'lock.lock_1'},
+        blocking=True)
+    # Assert
+    state = hass.states.get('lock.lock_1')
+    assert state is not None
+    assert state.state == 'unlocked'
+
+
+async def test_update_from_signal(hass, device_factory):
+    """Test the lock updates when receiving a signal."""
+    # Arrange
+    device = device_factory('Lock_1', [Capability.lock],
+                            {Attribute.lock: 'unlocked'})
+    await setup_platform(hass, LOCK_DOMAIN, device)
+    await device.lock(True)
+    # Act
+    async_dispatcher_send(hass, SIGNAL_SMARTTHINGS_UPDATE,
+                          [device.device_id])
+    # Assert
+    await hass.async_block_till_done()
+    state = hass.states.get('lock.lock_1')
+    assert state is not None
+    assert state.state == 'locked'
+
+
+async def test_unload_config_entry(hass, device_factory):
+    """Test the lock is removed when the config entry is unloaded."""
+    # Arrange
+    device = device_factory('Lock_1', [Capability.lock],
+                            {Attribute.lock: 'locked'})
+    config_entry = await setup_platform(hass, LOCK_DOMAIN, device)
+    # Act
+    await hass.config_entries.async_forward_entry_unload(
+        config_entry, 'lock')
+    # Assert
+    assert not hass.states.get('lock.lock_1')
diff --git a/tests/components/smartthings/test_switch.py b/tests/components/smartthings/test_switch.py
index a8013105291f..15ff3adce86c 100644
--- a/tests/components/smartthings/test_switch.py
+++ b/tests/components/smartthings/test_switch.py
@@ -126,7 +126,7 @@ async def test_update_from_signal(hass, device_factory):
 async def test_unload_config_entry(hass, device_factory):
     """Test the switch is removed when the config entry is unloaded."""
     # Arrange
-    device = device_factory('Switch', [Capability.switch],
+    device = device_factory('Switch 1', [Capability.switch],
                             {Attribute.switch: 'on'})
     config_entry = await _setup_platform(hass, device)
     # Act