Sir John Kennedy (26 September 1838 – 25 October 1921) was a Canadian civil engineer.
He was born at Spencerville, Upper Canada, and was educated at McGill University.
In 1863 he was appointed assistant city engineer of Montreal, Quebec.
In 1875-1907 he was chief engineer of the Montreal harbour commission.
He was a member of several royal commissions for engineering purposes connected with the Lachine Canal, the causes of floods at Montreal, and the completion of the Trent Valley Canal system.