The name is derived from a German diminutive form of Magdalena and Helene.
It has been used as an independent given name since at least the early part of the 20th-century.
Its recent popularity in Germany may be due to Heidi Klum, who named her daughter Leni in 2004.
Leni is currently the 23rd most popular female name in Germany, (2011).
The name is also occasionally used in Norway and Sweden.