Surname สมเสถียร (Stable 
, สมเสถียร 
, Somsathian ) , all around the world, is quite a rare cognomen. The last name สมเสถียร is habitual in Cuba, where it is quite a rare surname, Uruguay, and United Arab Emirates, where it is a rare surname. Not in comparison with a country's population, it is the most numerous in Cuba, Myanmar, and France. Likewise, สมเสถียร is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Stable | Myanmar, France, Argentina, United States, Cuba |
| สมเสถียร | Thailand |
| Somsathian | United States, Thailand |