Diana Gantner is a German voice actress and stage actress born on September 16, 1980, in Stuttgart, Germany. She trained at the Theaterakademie Köln, completing her studies in 2006, and has been active as a voice actor in dubbing and audiobook work since at least 2010.

Gantner has provided the German voice for characters in numerous anime series. Notably, she voices Saki Satou in the series Why the Hell are You Here, Teacher!? and Tsubaki Colbrand in Sword Oratoria: Is It Wrong to Try to Pick Up Girls in a Dungeon? On the Side. She is also the German voice for Kichiji Hananoya in the Haikara-San: Here Comes Miss Modern films.

Her other significant anime dubbing roles include Hatsune Wada in Two Car, Kerhilt Hietakannas in Knight's & Magic, Elvira in Izetta, die letzte Hexe, Nino's Mother in The Anonymous Noise, and Tomika Amato in Maken-Ki! Battling Venus. Beyond anime, her voice work encompasses dubbing for live-action films and television series, as well as audiobook narration for titles including the Katmere Academy series.

In addition to her voice work, Gantner maintains an active career in theatre, performing with various companies including the Komödie im Marquardt and the Württembergische Landesbühne Esslingen, and has received audience awards for her stage performances.