Cognomen นิลดวงแก้ว (นิลดวงแก้ว, Nildupkaew 
) , worldwide, is an extremely rare last name. The family name นิลดวงแก้ว is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| Nildupkaew | Thailand |