Williamsport is a city in and the county seat of Lycoming County, Pennsylvania, United States. In 2009, the population was estimated at 29,304. It is the principal city of the Williamsport, Pennsylvania Metropolitan Statistical Area, which has a population of about 117,000.Williamsport was settled by Americans late in the 18th century, and the town began to prosper due to its lumber industry. By the early 20th century, the town reached the height of its prosperity and the population has since declined by about a third from its peak of around 45,000 in 1950.Williamsport is the birthplace of Little League Baseball. South Williamsport, a town nearby, is the headquarters of Little League Baseball and annually hosts the Little League World Series in late summer.