Molloy or O'Molloy is an Irish surname, anglicised from O Maolmhuaidh, maolmhuadh meaning 'Proud Chieftain'. They were part of the southern Ui Neill, the southern branch of the large tribal grouping claiming descent from Niall of the Nine Hostages, the fifth-century king who supposedly kidnapped St Patrick to Ireland. They held power over a large part of what is now Co Offaly, where the surname is still very common. A second family were the O Maoil Aodha, 'descendant of the devoteee of (St) Aodh', from maol, literally 'bald', a reference to the distinctive tonsure sported by early Irish monks. As well as Molloy, this surname has also been anglicised as Mulloy, Malloy, Maloy, 'Miley' and 'Millea'. The name arose in east Connacht, in the Roscommon/east Galway region, and remains numerous there today.