Joel Allen Dewey (September 20, 1840 – June 17, 1873) was a Union Army colonel during the American Civil War. He was appointed a brigadier general of volunteers in November 1865, after the conclusion of the war, but he was mustered out on January 31, 1866 before his appointment was confirmed by the U.S. Senate on February 23, 1866. He was a post-war lawyer and district attorney general in Tennessee.