Blair County
Also known as Blair County, Pennsylvania, Blair County, PA
county in Pennsylvania, United States
Key facts
- Country
- United States
- State
- Pennsylvania
- Founded
- February 26, 1846
- Seat
- Hollidaysburg
- Largest city
- Altoona
- Total
- 527 sq mi (1,360 km )
- Land
- 526 sq mi (1,360 km )
- Water
- 1.3 sq mi (3.4 km ) 0.2%
- Estimate 2025
- 119,541
- Density
- 234/sq mi (90/km )
- Time zone
- UTC−5 ( Eastern )
- Summer dst
- UTC−4 ( EDT )
- Congressional district
Article
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.