Carlisle is a
borough in and the
county seat of
Cumberland County,
Pennsylvania,
United States. The name is locally pronounced as in
British English with emphasis on the second syllable . Carlisle is located within the
Cumberland Valley, a highly productive agricultural region. As of the
2010 census, the borough population was 18,682; the estimated population as of 2014 was 18,916. Including suburbs in the neighboring townships, 37,695 live in the Carlisle urban cluster. Carlisle is an
exurb of
Harrisburg, Pennsylvania, to the east.