John C. Williams may refer to:
John C. Williams (economist) (born 1962), American economist and central banker
John Carvell Williams (1821–1907), English nonconformist campaigner and Member of Parliament for Nottingham South and Mansfield
John Charles Williams (1861–1939), English Member of Parliament for Truro
John Charles Williams (cricketer), English cricketer
John Charles Williams (priest) (1912–2002), British Anglican priest
John Chester Williams (born 1953), American archer
John Christopher Williams (born 1941), Australian classical guitarist
John Constantine Williams Sr. (died 1892), co-founder of St. Petersburg, Florida
John Cornelius Williams Jr. (born 1938), American politician
