Thomas Macdonough, Jr. (21 December 1783–10 November 1825) is an early-19th-century American naval officer noted for his roles in the first Barbary War and the War of 1812.
He is the son of a revolutionary officer, Thomas Macdonough, Sr. who lives near Middletown, Delaware.
He is the sixth child of a family of ten siblings and is raised in the countryside.
He enters naval life at an early age, receiving a midshipman's commission at the age of sixteen.
Serving with Stephen Decatur at Tripoli, he is a member of "Preble's Boys", a select group of U.S. naval officers who serves under the command of Commodore Preble during the First Barbary War.
Macdonough achieves fame during the War of 1812, commanding the American naval forces that defeat the British navy at the Battle of Lake Champlain, part of the larger Battle of Plattsburgh, which helps lead to an end to that war.