John Horner

John Horner may refer to:

• John Henry Horner, also known as Cactus Jack (1927–2004), Canadian rancher, politician, and former cabinet minister
• John M. Horner, founder of Union City, California
• John S. Horner (1802–1883), American politician
• John Horner (British politician) (1911–1997), British firefighter, trade unionist and politician
• John Horner (organist) (1899–1973), organist, choirmaster and music teacher in South Australia
• John Horner (police), American chief of police of Los Angeles in 1885
• John R. Horner (born 1946), American paleontologist
• John Horner, a fictional character in The Adventure of the Blue Carbuncle, a Sherlock Holmes story by Sir Arthur Conan Doyle