Martina Duncker is a German former actress and voice actress, born in 1962. She has largely retired from her work in film and voice acting to pursue a career as a psychotherapist in Munich.

Duncker was notably active in providing German dubbing voices for characters in anime series and films. In this capacity, she voiced the character Risako Nagisa in the 2007 OVA series AIKa R-16: Virgin Mission. Another significant role was as the voice of Karla in the Record of Lodoss War OVA series and its sequel, Record of Lodoss War: Chronicles of the Heroic Knight. She also provided the German voice for Grandis Granva in Nadia: The Secret of Blue Water and its film adaptation, and for Aramis in the anime adaptation of The Three Musketeers. Her other anime voice work includes roles in Sailor Moon, where she voiced Sailor Star Maker, and in Doremi, Slayers, Trinity Blood, Mai-HiME, InuYasha, and the films Vampire Hunter D: Bloodlust and Tales from Earthsea.

Beyond anime, Duncker's extensive dubbing career encompassed German voice work for hundreds of live-action films and television series, lending her voice to actors such as Lucy Lawless, Laura Linney, Bebe Neuwirth, and Sandra Bernhard.