John Rees may refer to:
- John Rees (activist) (born 1957), British political activist and writer
- John Rees (cricketer) (1880–1959), Australian cricketer
- John Rees (journalist) (c. 1926), right-wing publisher and informant
- John Rees (musician) (1857–1949), Welsh musician
- John Rees (bassist) (born 1951), Australian bassist, known for being part of the classic line-up of rock band Men at Work
- Conway Rees (1870–1932), John Conway Rees, Welsh rugby union international
- Sir John Rees, 1st Baronet (1854–1922), colonial administrator in British India and member of parliament
- Sir John Milsom Rees (1866–1952), Welsh surgeon
- John Rawlings Rees (1890–1969), British psychiatrist
- John Rees-Evans (born 1978), British political candidate