Oceanus.
OceanusOrionOtus
If you mean "You", no - in fact there is no deities of either "Y" or "U"; but there are some "O".
AresApollo
Do you mean what Norse god starts with o? Odin is a Norse go that starts with O.
Iris was the god of the rainbow
In Greek mythology Chaos was the Greek god who created earth. His name begins with the letter C.
venus
God Bless you in Greek is O Theós na ev̱logeí.
There are no greek god/goddesses starting with Q.
o my god
Xuthus, better known has Greek Goddess Hellen's son, but he was not really a god just a mythical ancestor of the Achaeans and Ionians. There was no Greek God or Goddess that's name starts with an X really.
None.