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

Derr Run begins in a small pond on a hill in Penn Township.

[1] Derr Run joins Little Muncy Creek 13.09 miles (21.07 km) upstream of its mouth.

[3] In 2014, Waste Management of Pennsylvania, Inc. was issued an Erosion and Sediment Control Permit for which the receiving waterbody is Derr Run.

[5][6] Derr Run was entered into the Geographic Names Information System on August 2, 1979.