Richard Mentor Johnson (October 17, 1780 or 1781 – November 19, 1850) was the ninth Vice President of the United States, serving in the administration of Martin Van Buren (1837–1841). He is the only vice president ever elected by the United States Senate under the provisions of the Twelfth Amendment. Johnson also represented Kentucky in the U.S. House of Representatives and Senate; he began and ended his political career in the Kentucky House of Representatives.

Johnson was elected to the U.S. House of Representatives in 1806. He became allied with fellow Kentuckian Henry Clay as a member of the War Hawks faction that favored war with Britain in 1812. At the outset of the War of 1812, Johnson was commissioned a colonel in the army. He and his brother James served under William Henry Harrison in Upper Canada. Johnson participated in the Battle of the Thames. Some reported that he personally killed the Shawnee chief Tecumseh, which he later used to his political advantage.

Following the war, Johnson returned to the House of Representatives. The legislature appointed him to the Senate in 1819 to fill the seat vacated by John J. Crittenden. As his prominence grew, his interracial relationship with Julia Chinn, an octoroon slave, was more widely criticized. It worked against his political ambitions. Unlike other upper class leaders who had African American mistresses but never mentioned them, Johnson openly treated Chinn as his common law wife. He acknowledged their two daughters as his children, giving them his surname, much to the consternation of some of his constituents. The relationship is believed to have led to the loss of his Senate seat in 1829, but his Congressional district returned him to the House the following year.

In 1836, Johnson was the Democratic nominee for vice-president on a ticket with Martin Van Buren. Campaigning with the slogan "Rumpsey Dumpsey, Rumpsey Dumpsey, Colonel Johnson killed Tecumseh", Johnson fell just short of the electoral votes needed to secure his election. Virginia's delegation to the electoral college went against the state's popular vote and refused to endorse Johnson. However, he was elected to the office by the Senate, which was dominated by Democrats.

Johnson proved such a liability for the Democrats in the 1836 election that they refused to renominate him for vice-president in 1840. Van Buren campaigned without a running mate. He lost to William Henry Harrison, a Whig. Johnson tried to return to public office but was defeated. He finally was elected to the Kentucky House of Representatives in 1850, but he died on November 19, 1850, just two weeks into his term.