Carlen is of Swedish origin, derived from the Old Norse elements 'kar' meaning 'strong' and 'ljonn' meaning 'lion'. It is a unisex name, although it's more commonly used for females in Sweden. The name Carlen has gained some international recognition due to its usage by celebrities such as Swedish singer Carola Häggkvist, known for winning the Eurovision Song Contest in 1991. The name's popularity has seen fluctuations over time in Sweden, with its peak occurring in the late 20th century. Despite its Swedish origins and history, Carlen is not widely used outside of Scandinavia, making it quite unique internationally.
"Carlen as a name has experienced periods of popularity with peaks in the late 1930s and early 1940s, again in the late 1960s to mid-1970s, and most recently around the turn of the century. However, it seems to have seen a decline since the 2010s."