Sylvester Graham, (born July 5, 1794, West Suffield, Conn., U.S.—died Sept. 11, 1851, Northampton, Mass.), American clergyman whose advocacy of a health regimen emphasizing temperance and vegetarianism found lasting expression in the graham cracker, a household commodity in which lay the origin of the modern breakfast-cereal industry.
After working at a variety of odd jobs, Graham became a Presbyterian minister in 1826 but preached little. He is best known for his advocacy of unsifted, coarsely ground wheat (graham) flour and his invention of the graham cracker (1829). At the height of his popularity, Graham lectured widely. He recommended a complete health regimen, including hard mattresses, cold showers, and a diet consisting of homemade bread (he was attacked once by a mob of bakers and butchers), rough cereals, fruits, and vegetables. Temperance (Graham) boardinghouses opened in New York City and Boston, and many Grahamites lived at Brook Farm (near Boston), a famous experiment in communal living.