Justice Buchanan may refer to:
Alexander McKenzie Buchanan (1805–1868), associate justice of the Louisiana Supreme Court Archibald C. Buchanan (1890–1979), associate justice of the Supreme Court of Virginia Arthur S. Buchanan (1856–1919), associate justice of the Tennessee Supreme Court John Buchanan (Maryland judge) (1772–1844), associate justice and chief justice of the Maryland Court of Appeals John A. Buchanan (1843–1921), associate justice of the Supreme Court of Virginia Peter Buchanan (judge) (1943–2014), judge of the Supreme Court of Victoria