Cognomen Undasan (Undasan 
) , in the world, is a very rare last name. The family name Undasan is characteristic of Singapore, where it is a rare surname, the United Kingdom, where it is a very rare surname, and Philippines, where it is an extremely rare surname. Much less frequently, Undasan is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Undasan | Philippines, Singapore, India, United Kingdom |