O'Hanigan is an Irish surname, a variant of O'Hannigain, which itself derives from O'Hannagain. The root form, Ó hAnnagáin, means "descendant of Annagán," where Annagán is a diminutive of the personal name Annadh, meaning "delay." This surname is part of a larger family of Irish surnames sharing the same origin, including Hanegan, Hanigan, Hannigan, Hannigen, O'Hanegan, and O'Hannagain. These variant forms reflect the historical anglicization of Irish patronymics, often with simplification of the Gaelic prefix and phonetic spelling variations. The prefix Ó indicates "grandson" or "male descendant," a common feature of many Irish surnames. The name Annagán itself is obscure, but the root element annadh meaning "delay" suggests the name may have originally been a nickname or given name referencing a characteristic or circumstance. As a family name, O'Hanigan likely originated in a specific region in Ireland, though due to the scarcity of records and the evolution of spelling variants, pinpointing its exact historical clann is difficult. Key Facts Meaning: Descendant of Annagán Origin: Irish Type: Patronymic surname Variants: Hanegan, Hanigan, Hannigan, Hannigen, O'Hanegan, O'Hannagain, O'Hannigain