Hummelstown is a borough in Dauphin County, Pennsylvania, United States. The population was 4,535 as of the 2020 census. It is part of the Harrisburg–Carlisle Metropolitan Statistical Area. Originally named Fredrickstown, the town was established in 1762. Hummelstown is a Tree City and is located in District 15 of the Pennsylvania State Senate. It is centrally located between Harrisburg and Hershey, making it a common tourist drive-through.