Denis Stairs OBE, B.Eng. (May 3, 1889 – January 14, 1980) was a Canadian engineer and businessman. He was born in Halifax, Nova Scotia, the son of George Stairs, a founding partner and president of Royal Securities Corporation. A graduate of Dalhousie University, Denis Stairs studied at MIT then as a director of Royal Securities he became associated with entrepreneur and press baron Sir Max Aitken (later Lord Beaverbrook) and Izaak W. Killam. In 1922, he relocated to Montreal, Quebec, where he worked as an assistant engineer for Killam's Montreal Engineering Company, Ltd., rising to vice-president and eventually chairman of the board of directors.