Octriallach

Son of indech of the Fomorii, Killed by ogma at the second battle of Magh Tuireadh.(Irish)

Ocelos

God of the Silures . Also invoked at Carlisle. Celtic origin

Ogma

God of Eloquence and Literature. A son of the Dagda. He was skilled in dialects and poetry as well as being a warrior. He also had a role in conveying souls to the Otherworld. He was called ogma Grian-aineach (of the Sunny Countenance) and Ogma Cermait (of the Honeyed Mouth). Credited with the invention of Ogham. (Irish)

Ogmia

The British equivalent of Ogma and Ogmios.

Ogmios

The Gaulish God cognate with Ogma in Irish mythology.

Oirbsen

The alternative name for Manannan Mac Lir. Loch Oirbsen is the ancient name for the place where the Sea God was said to have met his death. (Irish)

Oisin

Son of Fionn Mac Cumhail and the Goddess Sadb, Daughter of the Bodb Dearg. (Irish)

Olloudius

Great Tree, worshipped in Antibes by the Nabonenses as a War God.

Oonagh

Wife of Fionnbharr, relegated from an ancient Goddess of the De Danaan in popular folklore to "queen of all the fairies in Ireland". (Irish)

Oscar

Grandson of Goddess Sadb and Fionn Mac Cumhail. (Irish)