Cumberland County is a county in the U.S. state of Pennsylvania. As of the 2020 census, the population was 259,469.[1] Its county seat is Carlisle.[2] [1]"QuickFacts: Cumberland County, Pennsylvania". United States Census Bureau. Retrieved August 18, 2023.[2]"Find a County". National Association of Counties. Archived from the original on May 31, 2011. Retrieved June 7, 2011. This short article about a place or feature in the United States can be made longer. You can help Wikipedia by adding to it.