John Fryer may refer to:

• John Fryer (physician) (died 1563), English physician, humanist and early reformer
• John Fryer (physician, died 1672), English physician
• John Fryer (travel writer) (1650–1733), British travel-writer and doctor
• Sir John Fryer, 1st Baronet (1671–1726), Lord Mayor of London
• John Fryer (Royal Navy officer) (1753–1817), sailing master on the Bounty
• Sir John Fryer (British Army officer) (1838–1917), British Army general
• John Fryer (sinologist) (1839–1928), educator, translator, scientist
• Sir John Fryer (entomologist) (1886–1948), English entomologist
• John Denis Fryer (1895–1923), Australian soldier and university student
• John E. Fryer (1938–2003), psychiatrist and gay rights activist
• John Fryer (producer) (born 1958), rock producer