John Francis Seitz, A.S.C. (June 23, 1892 – February 27, 1979) was an American cinematographer and inventor. He was nominated for seven Academy Awards.

Seitz's Hollywood career began in 1909 as a lab assistant with the Essanay Film Manufacturing Company in Chicago. He went to work as a lab technician for the American Film Manufacturing Company (known as "Flying A"), also in Chicago. In 1916, during the silent era, he established himself, achieving great successes with the Rudolph Valentino film The Four Horsemen of the Apocalypse (1921).