Last name ทันธะศิริ (ทันธะศิริ 
, Tanthasiri 
) , globally, is a very rare surname. The cognomen ทันธะศิริ is characteristic of Thailand, where it is a very rare surname, and the United States, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| ทันธะศิริ | Thailand |
| Tanthasiri | United States, Thailand |