Mertztown is a census-designated place[3] in Longswamp Township in Berks County, Pennsylvania.

[4] Mertztown is located in Berks County at latitude 40.506 and longitude -75.665.

It appears on the United States Geological Survey map for Topton and is in the Eastern Time Zone (UTC-5).

The Reading Railroad which ran through Mertztown, was later acquired by Norfolk Southern as the Reading Line, and remains a heavily used railroad branch.

A branch of the Catasauqua and Fogelsville Railroad once passed through the Farmington and Klines Corner section in Mertztown, but the tracks were later removed.