Ó Caomhain is an Irish surname that translates to "descendant of Caomhán," with "Caomhán" meaning "little saint." This name is associated with several notable families in Ireland, particularly in the province of Connacht. The Ó Caomhain family has historical ties to the Gaelic nobility and is often linked to the Sligo region. Variants of the name include Cahill and Cavanagh, reflecting the diverse ways Irish surnames have evolved over time. The name is also connected to various cultural and genealogical studies in Ireland.