Mars Hill was named by a British Army chaplain in 1790, who held a service on the hill and likened it to the hill in Athens dedicated to Mars, where the Apostle Paul had declared the unknown God to the Athenians. The first permanent settlers came from nearby New Brunswick in 1844 to grow potatoes, an agricultural resource still important to the region. Mars Hill was incorporated on February 21, 1867 from Mars Hill Plantation.
Mars Hill is located where United States Route 1 splits, forking to Presque Isle while Route 1A leads to Fort Fairfield.