Cox Run is a tributary of Little Muncy Creek in Lycoming County, Pennsylvania, in the United States.

Cox Run itself flows through a valley known as Neufer Hollow and is designated as a Coldwater Fishery.

Cox Run begins in a valley to the east of Buck Hill in Moreland Township.

[1] Cox Run joins Little Muncy Creek 1.96 miles (3.15 km) upstream of its mouth.

[3] In 2008, Engineering District 3-0 of the Pennsylvania Department of Transportation applied for permission to carry out a bank stabilization project on Cox Run.