Cognomen Udomritthiruj (Udomritthiruj 
) , in all the world, is an extremely rare last name. The last name Udomritthiruj is characteristic of Thailand, where it is an extremely rare surname, and the United States.
| VARIANT | COUNTRY |
|---|---|
| Udomritthiruj | United States, Thailand |
| kamphol udomritthiruj Thai ichthyologist, TH (b. 1963) |
|