Surname Oeun (Oeun 
) , in all the world, is a rare family name. The surname Oeun is habitual in Cambodia, where it is a rare surname, Portugal, where it is a very rare surname, and the United States. Not in comparison with a country's population, the name is most common in the United States, Cambodia, and Canada. Also, Oeun is the forename as well as the last name.