Johnstown is a city in Cambria County, Pennsylvania, west-southwest of Altoona and 56 miles east of Pittsburgh. The population was 20,978 at the time of the 2010 census and estimated to be 19,195 in 2019. It is the principal city of the Johnstown, Pennsylvania, Metropolitan Statistical Area, which includes Cambria County. It is also part of the Johnstown-Somerset, PA Combined Statistical Area, which includes both Cambria and Somerset Counties.