The Massachusetts General Court granted Otis Field Plantation in 1771 to James Otis and other heirs of Captain John Gorham and his company for their service in the 1690 Battle of Quebec. It replaced a 1736 grant which had been ruled invalid. In 1797, the plantation was incorporated as Otisfield. On March 8, 1805, Harrison was set off and incorporated from portions of Otisfield and Bridgton. It was named after a principal landowner, Harrison Gray Otis of Boston, the heir of James Otis.