what county is hummelstown pa in?
Hummelstown, PA. Sponsored Topics. Hummelstown is a borough in Dauphin County, Pennsylvania, United States. The population was 4,360 as of the 2000 census. It is part of the HarrisburgâCarlisle Metropolitan Statistical Area. Fredrickstown was the original village of present-day Hummelstown; it was established in 1762.