city, seat (1796) of Lycoming county, north-central Pennsylvania, U.S. It lies on the West Branch Susquehanna River, opposite South Williamsport, and in the foothills of the Allegheny Mountains, 75 miles (121 km) north of Harrisburg. The area was inhabited by Andastes Indians (a subgroup of the Susquehannock, or Susquehanna) prior to the arrival of Europeans. Founded in 1795, the settlement was supposedly named for William Russell, who had a boat landing on the river. It became a centre for lumbering in the 1860s. The “Sawdust War” erupted (1872) as workers sought a shorter work day (they eventually won a 10-hour day). The militia put it down. As the timber supply diminished, the economy diversified, eventually including metal and leather products, furniture, processed foods, and textiles.

Williamsport is the seat of Lycoming College (1812) and Pennsylvania College of Technology (1989), which is part of the Pennsylvania State University system. The city is also the site of Little League Baseball International Headquarters (Little League) and hosts the Little League World Series annually (in August) in the Little League World Series Stadium. The city's historic district has Victorian mansions that were once the homes of lumber barons. Inc. borough, 1806; city, 1866. Pop. (2000) city, 30,706; Williamsport MSA, 120,044; (2006 est.) city, 29,814; Williamsport MSA, 117,668.