Surname Риу (Riou 
, Rioux , Риу 
) , in the entire world, is a common last name. The cognomen Риу is habitual in Seychelles, where it is quite a common surname, France, and Mauritius (explore the name in all countries). Not in comparison with a country's population, this name is the most popular in France, Canada, and the United States. Very seldom, Риу is the forename as well as the last name.