John B. Williams may refer to:
- John B. Williams (disc jockey) or John B (born 1977), English disc jockey
- John B. Williams Jr. (born 1941), American bassist
- John Beaumont Williams (1932–2005), Australian botanist
- John Bell Williams (1918–1983), American politician
- John Benson Williams or Ian Rotten (born 1970), American wrestler
- John Brodie Williams or Johnnie Williams (1889–1963), American baseball player
- John Burr Williams (1900–1989), American economist
- John B. Williams (general), United States Air Force general
- Sir John Bickerton Williams, English nonconformist author and lawyer