Polk Valley Run is a tributary of Saucon Creek in Northampton County, Pennsylvania. It is approximately 1.9 miles (3.1 km) long and flows through Lower Saucon Township and Hellertown. The watershed of the stream has an area of 2.13 square miles (5.5 km2). A reach of the stream is designated as an impaired waterbody due to siltation from agriculture. However, wild trout and other wildlife are present in and around it. Most of the watershed is forested.