Oceanus ( ; Greek: Ὠκεανός "Ōkeanós", ] ), also known as Ogenus ("Ogenos", Ωγηνος) or Ogen (Ωγην), was a divine figure in classical antiquity, believed by the ancient Greeks and Romans to be the divine personification of the sea, an enormous river encircling the world.
Oceanus was worshipped by the Celts
Oceanus was a Greek/Roman god, not a Celtic god.