Family name ธีรยาจิรธัญญ์ (ธีรยาจิรธัญญ์ 
) , around the globe, is an extremely rare cognomen. The cognomen ธีรยาจิรธัญญ์ is habitual in South-eastern Asia, particularly Thailand, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| ธีรยาจิรธัญญ์ | Thailand |