Judge Duncan may refer to:
Allyson K. Duncan (born 1951), judge of the United States Court of Appeals for the Fourth Circuit Charles T. Duncan (1838–1915), judge of the county court of Lee County, Virginia John Alton Duncan (1932–2007), judge of the Manitoba Superior Court Kyle Duncan (judge) (born 1972), judge of the United States Court of Appeals for the Fifth Circuit Richard M. Duncan (1889–1974), judge of the United States District Courts for the Eastern and the Western Districts of Missouri Robert Morton Duncan (1927–2012), judge of the United States District Court for the Southern District of Ohio
See also Justice Duncan (disambiguation)