Sir John Douglas Hazen KCMG PC (June 5, 1860 – December 27, 1937) was a politician in New Brunswick, Canada. Known by his second name, Douglas, he entered politics in 1885 when he was elected as an alderman for Fredericton City Council. He became mayor in 1888. Hazen was elected to the House of Commons of Canada as a Conservative candidate in the 1891 federal election. He lost his seat in the 1896 election that defeated the Conservatives and brought Wilfrid Laurier's Liberals to power. Hazen was the father of King Hazen.