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

• Jonny Rees, Hong Kong rugby union player
• Jonny Rees (model), Mr. Wales 2008
• John Reese (disambiguation)
• John Rhys (1840–1915), scholar
• John Rhys-Davies (born 1944), Welsh actor