Last name Koam (Koam 
) , all over the world, is a very rare family name. The family name Koam is habitual in Cambodia, where it is a rare surname, France, where it is a very rare surname, and the United States, where it is an extremely rare surname. In absolute terms, this name is the most popular in the United States, India, and Cambodia. Very seldom, Koam is the forename as well as the last name.