The Commonwealth of Pennsylvania ( /ˌpɛnsɨlˈveɪnjə/ ) is a state located in the Northeastern and Middle Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada to the north, and New Jersey to the east. The state's four most populous cities are, respectively, Philadelphia, Pittsburgh, Allentown and Erie. The state capital is Harrisburg.

Pennsylvania has 51 miles (82 km) of coastline along Lake Erie and 57 miles (92 km) of shoreline along the Delaware Estuary.