Mars Hill is a census-designated place (CDP) comprising the main village within the town of Mars Hill in Aroostook County, Maine, United States.

Prior to 2010, the village was part of the Mars Hill-Blaine CDP.

The Mars Hill CDP is located near the southwestern corner of the town of Mars Hill, bordered by the town and CDP of Blaine to the south.

U.S. Route 1 runs through the center of the CDP, leading northwest 14 miles (23 km) to Presque Isle and south 27 miles (43 km) to Houlton.

According to the United States Census Bureau, the Mars Hill CDP has a total area of 2.2 square miles (5.6 km2), of which 2.1 square miles (5.5 km2) is land and 0.039 square miles (0.1 km2), or 1.48%, is water.