John Gwynne, Gwynn or Gwyn may refer to:
Politicians John W. Gwynne (1889–1972), Republican U.S. representative from Iowa John Gwynne (MP for Bath) (), English member of parliament (MP) John Gwynne (MP for Caernarvonshire) (died 1574), MP for Caernarvonshire (UK Parliament constituency) John Gwyn (MP for Cardigan) (), MP for Cardigan (UK Parliament constituency) John Gwynne (MP for Wareham) (), MP for Wareham (UK Parliament constituency)
People in sport John Tudor Gwynn ("Jack", 1881–1956), Irish cricketer and reporter in British India John David Gwynn (1907–1998), Irish cricketer and civil engineer John Gwynne (commentator) (1945–2022), British sport reporter and commentator
Others John Gwynne (captain) (), Welsh soldier John Gwynn (architect) (1713–1786), British architect and civil engineer John Gwyn (philanthropist) (1755–1829), Derry linen merchant and benefactor John Wellington Gwynne (1814–1902), Canadian lawyer and Supreme Court judge John Gwynn (Syriacist) (1827–1917), Irish Syriacist and Anglican dean John Gwynne (author) (born 1968), British fantasy writer