Daniel Duncan McKenzie (1859-1927) was interim leader of the Liberal Party of Canada in 1919, following the death of Sir Wilfrid Laurier on February 17, 1919.

He held that position, and consequently also the position of leader of the Official Opposition, until William Lyon Mackenzie King assumed the party leadership on August 7 of the same year.

He later served as Solicitor General during King's second term in office.