Family name Oyay (Oyay 
) , throughout the world, is a rare cognomen. The family name Oyay is characteristic of Sudan, where it is a rare surname, Philippines, where it is a very rare surname, and Australia. Very seldom, Oyay is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Oyay | United Kingdom, Sudan, Australia, Philippines, India |
| oyay deng ajak South Sudan's Minister for Investment, SS (b. 1962) |
|