Duncan MacIntyre or Duncan McIntyre may refer to:

• Duncan Ban MacIntyre (1724–1812), Scottish Gaelic poet
• Duncan MacIntyre (New Zealand politician) (1915–2001), New Zealand politician
• Duncan McIntyre (businessman) (1834–1894), Canadian businessman
• Duncan McIntyre (explorer) (1831–1866), Australian explorer
• Duncan A. McIntyre, American aviation pioneer
• Duncan John McIntyre (1842–1920), Canadian lawyer and political figure from Ontario