Ó Galáin
Ó GALÁIN, Ó GALLÁIN—I—O Gallane, O Gallon, Gallen, Gallon, Gollan; 'descendant of Gallán' (diminutive of gall, a cock), or 'Galán' (diminutive of gal, valour); the name of a Breifney family who were anciently chiefs of Clann Dunghalaigh; still in Co. Leitrim, anglicised Gallon; also in Donegal.
Alphabetical Index to Irish Surnames