Markus Schleinzer (born 8 November 1971; Vienna) is an Austrian film director, screenwriter, casting director, and actor. He is best known his feature films Michael (2011) and Rose (2026).

Before establishing as a filmmaker, Schleinzer built a long career as a casting director, working on more than 60 Austrian film and television productions and collaborating with directors including Michael Haneke, Ulrich Seidl, and Jessica Hausner. His background in casting has been widely cited by Schleinzer as a formative influence on his approach to acting and staging as a director.