Family History and Genealogy Resources by Surname
O'Byrne Surname Origin
Originally O'Bran, the descendants of Bran, an ancient king of Leinster; which signifies a raven; he was usually called Bran Duv, the black raven, from the color of his hair, and his thirst of prey.
Source: An Etymological Dictionary of Family and Christian Names With an Essay on their Derivation and Import; Arthur, William, M.A.; New York, NY: Sheldon, Blake, Bleeker & CO., 1857.
O'Byrne Surname Meaning and Family Facts
There is more to O'Byrne family history than the origin of your surname:
A O'Byrne Family History Thought:
'If you would not be forgotten,
As soon as you are dead and rotten,
Either write things worthy of reading,
Or do things worthy of writing.' --Benjamin Franklin, May 1738