Jethro Exum Sumner (1733 – 18 March 1785) was a brigadier general in the Continental Army during the American Revolutionary War.
Sumner was born in Virginia. He was active in the measures that preceded the Revolution, and in 1760 was paymaster of the provincial troops of North Carolina and commander at Fort Cumberland. He was also a commissioned officer in the Virginia Regiment during the French and Indian War. In 1776 he was appointed by the Provincial congress colonel of the 3rd North Carolina Regiment, and served under George Washington in the north. He was commissioned brigadier-general by the Continental Congress in 1779, was ordered to join General Horatio Gates in the south, and was at the Battle of Camden in 1780. He then served under General Nathanael Greene, and at the Battle of Eutaw Springs, September 8, 1781, made a bayonet charge, after which he was active in keeping the Tories in check in North Carolina until the close of the war.
Sumner was active after the war in the creation of North Carolina's chapter of the Society of the Cincinnati, serving as its first president.
He died in Warren County, North Carolina. Sumner County, Tennessee (originally part of North Carolina) was named for him.