Leo Steiner (c. 1939 – December 31, 1987) was an American restaurateur who was co-owner of the Carnegie Deli, located next to Carnegie Hall at 55th Street and Seventh Avenue in the New York City borough of Manhattan. While his partner, Milton Parker, mostly worked behind the scenes, Steiner worked the crowd with his Jewish humor in the restaurant, which became a destination for both celebrities and tourists in the theater district.