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
- Richard M. Ketchum (1922–2012), American historian and magazine editor
- Robert Glenn Ketchum (born 1947), landscape and nature photographer
- Rosemary Ketchum, American politician and community organizer
- 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