Aspinwall is a borough on the Allegheny River in Allegheny County, Pennsylvania, United States, and is part of the Pittsburgh Metro Area. It is essentially a residential place. In 1900, 1,231 people resided in Aspinwall, and that number rose to 2,592 in 1910, and 3,170 by 1920. The population was 2,801 at the 2010 census.