Carlisle is a borough in and the county seat of Cumberland County, Pennsylvania. Carlisle is located within the Cumberland Valley, a highly productive agricultural region. As of the 2020 census, the borough population was 20,118; Including suburbs in the neighboring townships, 37,695 live in the Carlisle urban cluster. Carlisle is the smaller principal city of the Harrisburg−Carlisle Metropolitan Statistical Area, which includes all of Cumberland, Dauphin, and Perry counties in South Central Pennsylvania. In 2010, Forbes rated Carlisle and Harrisburg the second-best place to raise a family.