Somerset is a borough in Somerset County, Pennsylvania, United States. The population was 6,277 at the 2010 census. The borough is surrounded by Somerset Township. It is the county seat of Somerset County. Somerset is just off Exit 110 of the Pennsylvania Turnpike (I-70 and I-76). Somerset is the principal city of the Somerset, PA Micropolitan Statistical Area, and is also one of two cities, the other being Johnstown, that make up the larger Johnstown-Somerset, PA Combined Statistical Area.