Family name Riisi (Ris 
, Ries , Riisi 
) , worldwide, is a common last name. The last name Riisi is habitual in Western Europe, particularly Luxembourg, where it is quite a common surname, Germany, and Switzerland. Not in comparison with a country's population, it most frequently occurs in Germany, the United States, and Indonesia. Much less frequently, Riisi is the forename as well as the last name.