Sewickley is a borough in Allegheny County, Pennsylvania, United States, 12 miles (19 km) west northwest of Pittsburgh along the Ohio River. It is a residential suburb of the Pittsburgh metropolitan area. The population was 3,907 at the 2020 census. The Sewickley Bridge crosses the Ohio River from Sewickley to Moon Township.

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.