Cognomen Уен (Uyen 
, Uen 
, Ouen 
) , in all the world, is quite a common family name. The last name Уен is characteristic of Vietnam, where it is quite a rare surname, Laos, and Bulgaria. Not in comparison with a country's population, it is commonest in Vietnam, China, and Malaysia. Also, Уен is the forename as well as the last name.