Chambersburg is a borough located in the South Central region of Pennsylvania, United States. It serves as the county seat of Franklin County and is situated within the Cumberland Valley, which is part of the larger Great Appalachian Valley. The borough is positioned approximately 13 miles north of the Maryland border and the Mason-Dixon line, and about 52 miles southwest of Harrisburg, the state capital.
According to the United States Census Bureau, the population of Chambersburg was 21,903 in 2020. When combined with the surrounding Greene, Hamilton, and Guilford Townships, the Greater Chambersburg area has a population of 66,340 people. The broader Chambersburg, PA Metropolitan Statistical Area includes all of Franklin County and had a population of 149,618 in 2010.