Family name Riys (Riys 
, Рийс 
) , across the world, is a rare cognomen. The cognomen Riys is habitual in Israel, where it is quite a rare surname, Bulgaria, where it is a rare surname, and Kazakhstan, where it is a very rare surname. In absolute terms, this name is the most popular in Israel, Bulgaria, and Russia. Likewise, Riys is the forename as well as the last name.