The stream is located in Hampshire County in the U.S. state of West Virginia's Eastern Panhandle.
[2] Dillons Run's source lies in a hollow along the southeastern end of Cooper Mountain (2,028 feet), south of the community of Millbrook.
At the northern end of Dillons Mountain, Dillons Run flows east, parallel to the Northwestern Turnpike (U.S. Route 50) and then under Cacapon River Road (County Route 14) before emptying into the Cacapon River south of the Capon Bridge.
This portion of the stream is situated approximately six miles southeast of Capon Bridge.
Dillons Run is stocked once in February and once every two weeks from March through May by the West Virginia Division of Natural Resources.