Ketchum is a surname that originated in England.

Notable people with the surname include:

• Annie Chambers Ketchum (1824–1904; (religious name, Sister Amabilis), American educator, lecturer, writer
• Daniel Ketchum (born 1981), former American swimmer
• Gerald Ketchum (1908–1992), commanded the icebreaker USS Burton Island (AG-88)
• Gus Ketchum (1897–1980), American Major League Baseball pitcher
• Hal Ketchum (1953–2020), American country music singer-songwriter
• Henry Ketchum (1839–1886), Canadian engineer
• Jack Ketchum (1946–2018), American horror writer
• James S. Ketchum (1931–2019), American psychiatrist
• Jesse Ketchum (1782–1867), tanner and political figure in Upper Canada
• Menis E. Ketchum, Chief Justice of the Supreme Court of Appeals of West Virginia
• Morris Ketchum (1796–1880), American banker and financier of the 19th century
• Richard Ketchum (1773–1845), political figure in New Brunswick
• Robert Glenn Ketchum (born 1947), landscape and nature photographer
• Tom Ketchum (1863–1901), a.k.a. "Black Jack" Ketchum, U.S. Western outlaw
• Wesley Harrington Ketchum (1878–1968), medical doctor, introduced Edgar Cayce to the national medical community in a 1910 presentation to the American Association for Clinical Research
• William Ketchum (mayor), mayor of the City of Buffalo, New York
• William M. Ketchum (1921–1978), U.S. Representative
• William Scott Ketchum (1813–1871), U. S. Army officer before and during the American Civil War

Fictional characters:

• Ash Ketchum, a fictional Pokémon Trainer figure
  • Delia Ketchum, his mother
• Kevin Ketchum, an OZ prisoner