Cognomen Tiyajai (Tiyajai 
) , worldwide, is a rare last name. The cognomen Tiyajai is habitual in Thailand, where it is a very rare surname, and India, where it is an extremely rare surname. More frequently, Tiyajai is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Tiyajai | India, Thailand |