About Pittsburgh

Pittsburgh ( PITS-burg) is a city in the Commonwealth of Pennsylvania and the county seat of Allegheny County. It is the second-most populous city in Pennsylvania, behind Philadelphia, and 68th-largest city in the U.S. with a population of 302,971 as of the 2020 census. The city anchors the Pittsburgh metropolitan area of Western Pennsylvania; its population of 2.37 million is the largest in both the Ohio Valley and Appalachia, the second-largest in Pennsylvania, and the 27th-largest in the U.S. It is the principal city of the greater Pittsburgh–New Castle–Weirton combined statistical area that extends into Ohio and West Virginia. Pittsburgh is located in southwest Pennsylvania at the confluence of the Allegheny River and the Monongahela River, which combine to form the Ohio River. Pittsburgh is known both as "the Steel City" for its more than 300 steel-related businesses and as the "City of Bridges" for its 446 bridges.