Family name Sivasak (Sivasak 
) , globally, is an extremely rare cognomen. Predominantly, Sivasak is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Sivasak | United States, Thailand |
Pechkom, Naewchan, Sailaemthong, Vongmanobkun, and Vanitcharuk