Cornplanter Run is a 2.76-mile-long (4.44 km)[4] tributary to Oil Creek in northwestern Pennsylvania in the United States.

Cornplanter Run rises just south of Fosters Corner and flows south to join Oil Creek just north of the city limits of Oil City, Pennsylvania.

Calaboose Run joins this creek about half-way through its course on the left.

Cornplanter Run is a second order stream at its mouth with Oil Creek.

Rainfall averages 44.53 inches (1,130.99 mm) per year.