Family name Уст (Oest 
, Уст 
, Oust 
) , throughout the world, is quite a rare cognomen. The last name Уст is habitual in Norway, where it is quite a rare surname, Denmark, and Netherlands. Not in comparison with a country's population, this name is the most popular in Germany, the United States, and Netherlands. Very seldom, Уст is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Oest | Netherlands, Germany, Denmark, United States, Norway |
| Уст | Kazakhstan, Russia, Ukraine |
| Oust | Canada, France, Norway, United States |