Robert Ellenstein (born June 18, 1923 in Newark, New Jersey) is an American stage, television and film actor.

The son of a Newark dentist, Robert Ellenstein grew up in that New Jersey city and saw his father go on to become its two-term mayor. He served in the Air Corps during World War II: earning a Purple Heart during his service, he began acting, directing and teaching in Cleveland, Ohio. A veteran of the "Golden Age" of live TV (he played Quasimodo in a live Robert Montgomery Presents (1950) version of "The Hunchback of Notre Dame"), Ellenstein made his first film in 1954 (MGM's Rogue Cop). He would also try his hand at directing television with an episode of the 1960s comedy, Love on a Rooftop. Ellenstein is still working in TV and regional theater. He played the Federation President in Star Trek IV: The Voyage Home (1986).

The son of a Newark dentist, Robert Ellenstein grew up in that New Jersey city and saw his father go on to become its two-term mayor. He got his feet wet acting-wise prior to serving with the Air Corps during World War II; earning a Purple Heart during his service, he began acting, directing and teaching in Cleveland, Ohio. A veteran of the "Golden Age" of live TV (he played Quasimodo in a live "Robert Montgomery Presents" (1950) version of "The Hunchback of Notre Dame"), Ellenstein made his first movie in 1954 (MGM's Rogue Cop (1954)) and is still going strong with jobs in TV and regional theater.