Cognomen Ponkhao (Ponkhao 
) , worldwide, is a very rare surname. The surname Ponkhao is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname. Much less frequently, Ponkhao is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Ponkhao | India, Thailand |
Sirintip, and Sireethorn