John De Mott (October 7, 1790 – July 31, 1870) was a U.S. Representative from New York. Born in Readington, New Jersey, De Mott moved to Herkimer County, New York, in 1793 with his parents, who settled in what is now the town of Lodi, Seneca County. He attended the common schools. He pursued an academic course. Major general of the Thirty-eighth Brigade of the State militia. Supervisor in the town of Covert in 1823 and 1824 and of Lodi in 1826, 1827, 1829, and 1830. He engaged in mercantile pursuits in Lodi, New York, for more than forty years. He served as member of the State assembly in 1833. He was an unsuccessful candidate for election in 1840 to the Twenty-seventh Congress.