Ó hAilín
Ó hAILÍN—I—O Hallyne, Hallin, Hallion, Allin, Allen; 'descendant of Ailín' (diminutive of ail, noble, rock, a 'pet' form of some name commencing with Ail-); also written Ó hAillín; a rare surname; found chiefly in Ormond and Offaly.
Alphabetical Index to Irish Surnames