Last name Слен (Sleen 
, Слен 
) , all around the world, is a rare family name. The surname Слен is characteristic of Netherlands, where it is quite a rare surname, Norway, where it is a rare surname, and Belgium, where it is a very rare surname. In absolute terms, it most frequently occurs in Netherlands, the United States, and Norway. Much less frequently, Слен is the forename as well as the last name.