John Donkin (1802–1854) was a British engineer. He was a son of Bryan Donkin and worked in this father's company in Bermondsey, primarily on paper-making equipment. He married Caroline Hawes, granddaughter of William Hawes, notable as founder of the Royal Humane Society. Caroline Hawes was the sister of Sir Benjamin Hawes, brother-in-law of Isambard Kingdom Brunel. John Donkin was the father of Bryan Donkin Junior and grandfather of Sydney Donkin. He was first cousin of William Fishburn Donkin.