Mosey Run is a 7.5 mi (12.1 km) long 1st order tributary to Oil Creek in Crawford County, Pennsylvania.

Mosey Run rises on the South Branch French Creek divide in Union Township, Pennsylvania.

Mosey Run then flows south-southeast through the Erie Drift Plain to Oil Creek at Lincolnville, Pennsylvania.

Mosey Run drains 180.95 square miles (468.7 km2) of area, receives about 46.2 in/year of precipitation, has a topographic wetness index of 463.09 and is about 54% forested.

This article related to a river in Pennsylvania is a stub.