Mont Alto is a borough in Franklin County, Pennsylvania, United States.

[4] John Funk built the first house in the borough (then unestablished) in 1817 on what is now Main Street.

In the beginning of the 20th century, Mont Alto contained one of the largest sanatoriums in the area for treatment of tuberculosis.

[8] It sits at the western base of South Mountain along the headwaters of the West Branch of Antietam Creek.

Mont Alto State Park is located in the creek valley, 1 mile (1.6 km) east of the borough.

Penn State Mont Alto is located at the intersection of Slabtown Road and Campus Drive; Route 233 passes by the university.