The 1863 Maine gubernatorial election took place on September 14, 1863, in order to elect the governor of Maine. The National Union candidate Samuel Cony won his first one-year term as governor against Democratic candidate Bion Bradbury.
During his campaign, Bradbury claimed that president Abraham Lincoln had violated the Constitution by suspending habeas corpus, and was a vocal opponent of emancipation. A controversy occurred where General Samuel J. Anderson claimed in an interview that Bradbury would withdraw Maine's troops from the American Civil War, Bradbury denied this and accused Anderson of libel.