Royalton is a borough in Dauphin County, Pennsylvania, United States. As of the 2003 census, the borough population was 963. It is part of the HarrisburgCarlisleMetropolitan Statistical Area. It shares it's ZIP code with neighboring Middletown. Royalton is located at 401118N764338W / 40.18833N 76.72722W / 40.18833; -76.72722 (40.188325, -76.727280).