Cognomen Thayarath (Thayarath 
) , across the world, is a rare last name. The surname Thayarath is habitual in Laos, where it is quite a rare surname, and India, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Thayarath | India, Laos |
Khamma, Lylavady, Phonmani, Vonevilayhong, and Theptheva