Keenan

Recorded as O'Keenan and more usually Keenan, this is an Irish surname. Found mainly in Ulster counties Fermanagh and Monaghan, it originates from the ancient pre-10th-century Gaelic name Ó Cianáin meaning "The descendant of the faithful one" or similar. It may not have been entirely coincidence that the clan was famous throughout the Medieval Period for producing both high-ranking members of the church, and early historians, in several cases the same thing. The first recorded scribe was Adam O' Caianain, who was also the canon of Lisgool in Fermanagh. He is mentioned in the annals known as the "Four Masters" as being the historian to the famous Maguires of County Fermanagh. It is said that in 1659 in Petty's Census of Ireland that the spelling was found as MacKeenan, but if so this spelling is now completely extinct and research suggests that the original recording may have been a clerical mistake.

• Keenan Garvey, Entrepreneur
• Keenan Allen, American football wide receiver
• Keenan Cornelius, American jiu-jitsu practitioner
• Keenan Clayton, American football linebacker
• Keenan Evans (born 1996), American basketball player
• Keenan Hollahan, pseudonym for advice columnist
• Keenan McCardell, former American football wide receiver
• Keenan Robinson, American football linebacker
• Kenan Thompson, American actor and comedian
• Keenen Ivory Wayans, American comedian, director and writer
• Keenan Wynn, American character actor

• Brian Keenan (Irish republican), Provisional IRA member
• Brian Keenan (musician born 1943), American musician
• Brian Keenan (writer), Irish journalist and hostage
• Brigid Keenan, British/Irish writer of best-selling memoirs "Diplomatic Baggage"
• Cathy Keenan, Canadian television actor
• Celia Keenan-Bolger, American stage actor and singer
• David Keenan, Scottish writer and musician
• Deborah Keenan, American poet and educator
• Don Keenan, Canadian ice hockey goaltender
• Donal Keenan, Irish Gaelic games administrator
• Edward L. Keenan, American historian of medieval Russia
• Frank Keenan, American stage and screen actor and director
• Frank Keenan (hurler) Irish hurling player
• Harold Keenan, English footballer
• Harry Keenan, American screen actor
• Helen Grace Scott Keenan, American journalist, OSS employee and Soviet spy
• Henry Francis Keenan, American journalist and author
• Jack Keenan (boxer) (1929-2009), Canadian boxer
• Joe Keenan (footballer), British footballer
• Joe Keenan (writer), American writer and playwright
• John Keenan (Medal of Honor), U.S. Army soldier
• John F. Keenan, American attorney and federal judge
• John R. Keennan (1940–2015), American baseball scout
• Joseph B. Keenan, chief prosecutor in the International Military Tribunal for the Far East
• Joseph Henry Keenan, American thermodynamicist
• Lillie Keenan (born 1996), American show jumping rider
• Luke A. Keenan (1872–1924), New York politician
• Maynard James Keenan, American singer of bands Tool, A Perfect Circle and Puscifer
• Mike Keenan, Canadian ice hockey manager
• Nancy Keenan, American politician and pro-choice campaigner
• Norbert Keenan, Australian politician
• Paddy Keenan, Irish uilleann piper
• Pepper Keenan, American musician with Corrosion of Conformity
• Peter Keenan ("Crackers" Keenan), former Australian rules footballer
• Peter Keenan (boxer), Scottish boxer of the 1940s, and 1950s
• Philip Childs Keenan (1908-2000), American astronomer
• Phuwaryne Keenan (born 1988), Thai singer
• Roy Keenan (1930-2003), Canadian boxer
• Sinead Keenan, Irish actress
• Shy Keenan, British author, child sexual abuse survivor, and founder of Phoenix Survivors
• Sterling James Keenan, American pro wrestler
• Tamra Keenan, British singer
• Terry Keenan, American broadcast television business correspondent
• Trish Keenan, English singer and composer
• Vernon Keenan, American law enforcement officer

Fictional

• Gareth Keenan, character from UK television series The Office