Stefan Lehnen is a German actor and voice actor born in 1969 in Orsoy, now part of Rheinberg, Germany. His professional career encompasses both on-screen performances in German film and television and extensive work in dubbing, particularly for anime series and films.

Lehnen has provided German voices for a number of notable anime characters. In the acclaimed science fiction series Pluto, he voices Professor Abullah, a scientist who plays a central role in the backstory of the 39th Central Asian War and the creation of the powerful robot Bora. He takes on the role of Shinichi Saimori, a key character from the family at the heart of the romantic fantasy series My Happy Marriage. In the military isekai series Saga of Tanya the Evil, Lehnen voices Reiner Neumann, an aerial mage and fourth company commander serving under Tanya in the Empire's 203rd Battalion. He is also the voice of Kaiou Retsu, a master of Chinese martial arts, in the long-running martial arts anime series Baki. Within the world of One Piece, Lehnen voices two different characters: the pirate Kapoty in the television special One Piece Special: Adventure of Nebulandia and Charlotte Oven, a powerful member of the Big Mom Pirates and the minister of brown-ing on Whole Cake Island. Additional anime voice roles credited to Lehnen include Eugen in Granblue Fantasy: The Animation, Meld Loggins in Arifureta: From Commonplace to World's Strongest, and Olba in The Eminence in Shadow.

Beyond anime, Lehnen has a substantial career as an audiobook narrator, having read the German versions of numerous thrillers and non-fiction titles, including works by authors such as Vince Flynn, James Rollins, and Phil Knight. His on-screen acting credits include appearances in many long-running German television series such as SOKO 5113, Der Alte, Medicopter 117, Die Rosenheim-Cops, and Sturm der Liebe, as well as the children's film The Wild Soccer Bunch 3. This body of work demonstrates a versatile career spanning live-action acting, dubbing for animation, and audiobook narration.