Warrior Run (also known as Warrior Run Creek) is a tributary of the West Branch Susquehanna River in Northumberland County, Pennsylvania, in the United States. It is 9.5 miles (15.3 km) in length. It has a watershed area of 21.6 square miles and the watershed is in Northumberland and Lycoming Counties. The main soil series in the watershed is the series and the main land uses are agriculture and forest. The communities of Watsontown, Turbotville, and McEwensville are all in or near the watershed. The Warrior Run watershed was inhabited by Europeans in the early 1770s. Several mills and forts were built along it.