Family name สิทธุ์ (Sit 
, สิทธุ์ 
) , all around the world, is a common surname. The cognomen สิทธุ์ is characteristic of Macao, where it is quite a common surname, Bermuda, and Hong Kong (explore the name in all countries). Not in comparison with a country's population, it most frequently occurs in India, Myanmar, and Hong Kong. Also, สิทธุ์ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Sit | China, Hong Kong, India, Myanmar, Taiwan |
| สิทธุ์ | Thailand |