Family name Riyasan (Riyasan 
) , around the globe, is a rare cognomen. The family name Riyasan is characteristic of Thailand, where it is a rare surname, Malaysia, where it is an extremely rare surname, and India. Likewise, Riyasan is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Riyasan | Thailand, India, Malaysia |