John Milton Brannan (July 1, 1819 – December 16, 1892) was a career American Army officer who served in the Mexican-American War and as a Union general in the American Civil War, in command of the Department of Key West in Florida and assigned to Fort Zachary Taylor. His first wife was the daughter of Colonel Ichabod Crane; she mysteriously disappeared after taking a ferry from Staten Island to lower Manhattan and was presumed to have been murdered.