Surname ศัย (Sai 
, ศัย 
) , throughout the world, is a widespread cognomen. The surname ศัย is characteristic of Mongolia, where it is a prevalent surname, Myanmar, where it is a common surname, and Malaysia, where it is quite a common surname (explore the name in all countries). Not in comparison with a country's population, it most frequently occurs in Myanmar, India, and Mongolia. More frequently, ศัย is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Sai | Myanmar, India, Mongolia, Malaysia, China |
| ศัย | Thailand |