Mexico is an unincorporated community and census-designated place (CDP) in Walker Township, Juniata County, Pennsylvania, United States.

[3] Mexico is located in central Juniata County at 40°32′36″N 77°21′17″W / 40.54333°N 77.35472°W / 40.54333; -77.35472 (40.543341, -77.354771),[4] in the western part of Walker Township.

PA 75 leads southwest 1.4 miles (2.3 km) across the Juniata River to Port Royal, and the William Penn Highway (old Routes 22/322) leads northwest 3 miles (5 km) to Mifflintown, the Juniata county seat.

According to the United States Census Bureau, the Mexico CDP has a total area of 1.1 square miles (2.8 km2), all land.

18.8% of all households were made up of individuals, and 9.8% had someone living alone who was sixty-five years of age or older.