Ó Marcaigh is an Irish Gaelic surname, the original form of the anglicized Markey. The name derives from the personal name Marcach, meaning "horse rider" or "horseman" in Gaelic. As a patronymic, Ó Marcaigh signifies "descendant of Marcach." The name belongs to a class of Irish surnames that reference occupations or skills, in this case horse-riding, which was a valued activity in medieval Gaelic society. The name is primarily found in Ireland, with historical concentrations in counties such as Galway and Mayo. According to surname distribution data from Forebears, it remains relatively uncommon. Like many Irish surnames, Ó Marcaigh experienced anglicization to Markey or sometimes Marky during the 19th and 20th centuries, particularly following the Great Famine and subsequent emigration. Variants include the separate surname Ó Marcacháin. Meaning: descends from Marcach ("horse rider") Type: surname, Irish Gaelic Origin: Ireland Usage regions: mainly western Ireland Anglicized forms: Markey, Marky