A river in west Dumfries and Galloway, the Tarf Water rises in New Luce Parish to the west of Craigairie Fell. It flows generally southeastwards for most of its course until a short distance beyond Tarf Bridge near Mark of Luce it turns northeastwards for just over 3 miles (5 km) before joining the River Bladnoch just east of Kirkcowan. Its total length is about 17 miles (27 km).