O'Hannigain is a surname of Irish origin, a variant form of O'Hannagain. The root name, O'Hannagain, derives from the Irish Ó hAnnagáin, meaning "descendant of Annagán." The given name Annagán is a diminutive of Annadh, an Irish personal name meaning "delay." O'Hannigain belongs to the broader family of surnames that began with the prefix Ó, indicating a grandson or male descendant, a common pattern in Irish surnames that often reflect an ancestral figure or characteristic.Background and VariantsAs a variant of O'Hannagain, O'Hannigain shares the same etymology and is one of several anglicized forms that emerged from the phonetic transcription of the original Irish name into English. Related variants include Hanegan, Hanigan, Hannigan, Hannigen, O'Hanegan, and O'Hanigan. The spelling O'Hannigain is relatively uncommon today, but reflected in historical records and genealogical data.DistributionAccording to Forebears, the surname O'Hannigain has limited distribution, with instances recorded primarily in the United States and perhaps Ireland, though it is extremely rare. The surname can be found among individuals of Irish descent who emigrated or retained the antiquated spelling.Key FactsMeaning: Descendant of AnnagánOrigin: IrishType: Patronymic surnameUsage Regions: Ireland, United States