Tanja Schleiff (born in 1973 in Erfurt) is a German actress.

The daughter of actors Renate Hundertmark and Klaus Schleiff, she trained in acting at the Felix Mendelssohn Bartholdy University of Music and Theatre in Leipzig. She began her career on stage, performing notably at the Residenztheater in Munich and the Schauspielhaus in Düsseldorf.

In cinema, she has appeared in several notable feature films, such as Oliver Hirschbiegel's Downfall (Der Untergang, 2004), Dominik Graf's The Red Cockatoo (Der rote Kakadu, 2006), and Ralf Westhoff's comedy Shoppen (2006). On television, she has featured in numerous series and television films, notably portraying Countess Esterházy in the historical series Sisi (2021–2024) and Edith in the drama series Charité (2017).