Chalmers Jack Mackenzie, CC CMG MC FRS FRSC (July 10, 1888 – February 26, 1984) was a Canadian civil engineer, chancellor of Carleton University, president of the National Research Council, first president of Atomic Energy of Canada Limited, first president of Atomic Energy Control Board and instrumental in the development of science and engineering education in Canada.He was born in St. Stephen, New Brunswick, the youngest of six children of James and Janet MacKenzie.