Family name Kornnatthaphat (Kornnatthaphat 
) , throughout the world, is a very rare last name. The cognomen Kornnatthaphat is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| Kornnatthaphat | Thailand |
Pattara, Prapaporn, and Praphaporn