Warm Spring Run is an 11.9-mile-long (19.2 km) non-navigable tributary stream of the Potomac River in Morgan County of West Virginia's Eastern Panhandle. It rises on the eastern side of Warm Springs Ridge (1,115 feet) and parallels U.S. Route 522 for most of its course. Warm Spring Run enters the Potomac River at Hancock. Warm Spring Run is primarily fed by springs on Warm Springs Ridge, the most well-known of these being the springs at Berkeley Springs State Park in Berkeley Springs through which it flows.