Robert Stack (born Charles Langford Modini Stack; January 13, 1919 May 14, 2003) was an American actor and TV host. He was best known for starring in The Untouchables as Eliot Ness and for hosting Unsolved Mysteries. He also had a lengthy film career, earning an Oscar nomination for Written on the Wind. Although he mostly acted in dramas, he did the occasional comedy such as To Be or Not to Be and Airplane! (in which he poked fun at his straight-laced persona).
- The Mortal Storm (1940): Otto.
- To Be or Not to Be (1942): Lieutenant Stanislav Sobinski.
- Written on the Wind (1956): Kyle Hadley.
- The Untouchables (1959-1963): Eliot Ness.
- The Last Voyage (1960): Cliff Henderson.
- 1941 (1979): Maj. Gen. Joseph W. Stilwell.
- Airplane! (1980): Captain Rex Kramer.
- Uncommon Valor (1983): MacGregor.
- The Transformers: The Movie (1986): Ultra Magnus.
- Unsolved Mysteries (1987-2002): Host.
- Caddyshack II (1988): Chandler Young.
- Joe Versus the Volcano (1990): Dr. Ellison.
- Beavis and Butt-Head Do America (1996): ATF Agent Flemming.
- Butt-Ugly Martians (2001): Stoat Muldoon.