O'Hanlon is an Irish surname associated with the Ó hAnluain sept. As with other similar names, the added prefix "O'" means "son of" (Hanlon).
Notable people with that surname include:
Ardal O'Hanlon, Irish comedianBill O'Hanlon, American psychologistEvan O'Hanlon, Australian ParalympianFergal O'Hanlon, Irish Republican Army memberGeorge O'Hanlon, American actorJohn O'Hanlon (chess player) (1876–1960), Irish chess masterJohn O'Hanlon (Lackaghmore) (1889–1920), Sinn Féin member shot during the Irish War of IndependenceJohn O'Hanlon (politician) (1872–1956), Irish politician and journalistJohn O'Hanlon (writer) (1821–1905), Irish priest and writerMichael E. O'Hanlon (born 1961), American policy consultantMichael F. O'Hanlon (1890–1967), Irish politicianPaddy O'Hanlon (1944–2009), Irish politicianPat O'Hanlon, (born 1991), Australian Rugby League playerRedmond O'Hanlon, a British writerRedmond O'Hanlon (outlaw), a 17th-century Irish guerrilla soldierRory O'Hanlon, an Irish politicianSean O'Hanlon, an English footballerSiobhán O'Hanlon, Sinn Féin politician, former Provisional IRAVirginia O'Hanlon, catalyst for "Yes, Virginia, there is a Santa Claus"