John de Witt
John de Witt may refer to:

 Johan de Witt (1625–1672), Dutch politician who was assassinated
 John L. DeWitt (1880–1962), U.S. general in World War II who helped initiate the Japanese-American internment
 John DeWitt (athlete) (1881–1930), American college football player and Olympic hammer thrower
 John H. DeWitt Jr. (1906–1999), American pioneer in radio broadcasting, radar astronomy and photometry
 John DeWitt (gridiron football) (born 1970), American arena football lineman
 John DeWitt, pseudonymous author of some of the Anti-Federalist Papers