Cognomen Rittiwai (Rittiwai 
) , all around the world, is a very rare last name. The family name Rittiwai is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| Rittiwai | Thailand |
Sompong, Taddanai, Phannachat, and Kittichanun