Family name Ōō (Ōō 
) , in all the world, is a rare surname. The last name Ōō is habitual in Myanmar, where it is a rare surname, Egypt, where it is a very rare surname, and China, where it is an extremely rare surname. Likewise, Ōō is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Ōō | China, Egypt, Myanmar |