Family name ไพธนโรจน์ (ไพธนโรจน์ 
) , across the world, is an extremely rare last name. The cognomen ไพธนโรจน์ is characteristic of South-eastern Asia, particularly Thailand, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| ไพธนโรจน์ | Thailand |