Ó hAodha is a Gaelic- Irish surname, that has commonly been Anglicised to Hayes or Hughes.

Now generally anglicised as O'Hea (in County Cork), Hughes or Hayes, Ó hAodha derives from Aodh, a personal name (meaning "fire") popular at all historical times throughout the Gaelic world.

It is the surname of at least ten unrelated families found in Gaelic Ireland, such as

• Ó hAodha of Muscraighe-Luachra/the Múscraige of Sliabh Luachra, now County Cork;
• Ó hAodha of Tír Chonaill (centered at Ballyshannon, County Donegal);
• Ó hAodha of Tír Eoghain (around Ardstraw, County Tyrone;
• Ó hAodha of Ulaid (around what is now Tynan, County Armagh;
• Ó hAodha of Airgíalla (centred on what is now Farney, County Monaghan;
• Ó hAodha of Dál Fiatach in Ulaid (now south County Down;
• Ó hAodha of Muintir Murchada in what is now County Galway.

• Flann Ua Aedha, Abbot of Aran, died 1110.
• Séamas Ó hAodha, member of the Gaelic League, fl. 1914 - 1922.

• http://www.irishtimes.com/ancestor/surname/index.cfm?fuseaction=Go.&UserID=
• http://www.failteromhat.com/pedigree.php