Clairton is a city in Allegheny County, Pennsylvania, United States. It is located along the Monongahela River and is part of the Pittsburgh metropolitan area. The population was 6,181 at the 2020 census. Under Pennsylvania legal classifications for local governments, Clairton is considered a third-class city. It is home to Clairton Works operated by U.S. Steel, the largest coke manufacturing facility in the United States.

Allegheny County is a county in Pennsylvania, United States. As of the 2020 census, the population was 1,250,578, making it the state's second-most populous county, after Philadelphia County. Its county seat and most populous city is Pittsburgh, Pennsylvania's second most populous city. The county is part of the Greater Pittsburgh region of the state, and is the center of the Pittsburgh media market.