Last name เธียรธัญญกิจ (เธียรธัญญกิจ 
) , all over the world, is a very rare family name. The surname เธียรธัญญกิจ is characteristic of South-eastern Asia, particularly Thailand, where it is a rare surname.
| VARIANT | COUNTRY |
|---|---|
| เธียรธัญญกิจ | Thailand |