Family name Thathai (Thathai 
) , all around the world, is a rare last name. The cognomen Thathai is characteristic of Thailand, where it is a rare surname, South Africa, where it is an extremely rare surname, and India. Much less frequently, Thathai is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Thathai | South Africa, India, Thailand |