Marsh Run is a tributary of Coles Creek in Luzerne County and Columbia County, in Pennsylvania, in the United States. It is approximately one mile (1.6 km) long and flows through Fairmount Township in Luzerne County and Sugarloaf Township in Columbia County. The stream's watershed has an area of 0.44 square miles (1.1 km2). Wild trout reproduce throughout the stream. It is named after marshes, which can be found in the vicinity of the stream.