Blair County, Pennsylvania

Blair County
Blair County Courthouse in Hollidaysburg
Location within the U.S. state of Pennsylvania
Pennsylvania's location within the U.S.
Coordinates: 40°28′N 78°21′W / 40.47°N 78.35°W / 40.47; -78.35
Country United States
State Pennsylvania
FoundedFebruary 26, 1846
SeatHollidaysburg
Largest cityAltoona
Area
  Total
527 sq mi (1,360 km2)
  Land526 sq mi (1,360 km2)
  Water1.3 sq mi (3 km2)  0.2%
Population
 (2020)
  Total
122,822
  Density234/sq mi (90/km2)
Time zoneUTC−5 (Eastern)
  Summer (DST)UTC−4 (EDT)
Congressional district13th
Websitewww.blairco.org
DesignatedApril 13, 1982

Blair County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 122,822. Its county seat is Hollidaysburg, and its largest city is Altoona. The county was created on February 26, 1846, from parts of Huntingdon and Bedford counties. The county is part of the Southwest region of the commonwealth.

Blair County comprises the Altoona, PA metropolitan statistical area. It is also part of the Altoona-Huntingdon, PA Combined Statistical Area, which includes Blair and Huntingdon counties.