John Adams Dix (July 24, 1798 – April 21, 1879) was Secretary of the Treasury, Governor of New York and Union major general during the Civil War. He was notable for arresting the pro-Southern Maryland legislature, preventing that divided border state from seceding, and for arranging a system for prisoner exchange via the Dix-Hill cartel, concluded in partnership with Confederate Maj. Gen. D.H. Hill.