Born as Tadeusz Zbigniew Danielewski in Radom, Poland, he served in the Polish Underground during World War II and eventually ended up in a concentration camp. He and his then wife, actress Sylvia Daneel (née Sylwia Jadwiga Łakomska), emigrated to the United States in 1948. Early in the 1950s, they attended the University of Iowa. They were naturalized as United States citizens on April 19, 1954 through a Special Act of Congress. The couple later divorced.
After the war, he studied at the Royal Academy of Dramatic Art in London and started the Professional Actors Workshop in New York City, whose students included Martin Sheen, James Earl Jones, and Mercedes Ruehl. He was president of Stratton Productions, Inc. (NYC), a firm engaged in stage, film and TV productions.
He worked at NBC as a studio supervisor and helped develop a new method for directing TV programs. In 1983, he provided the Polish translation of "Sweet Georgia Brown" for Mel Brooks's To Be or Not to Be. He worked at the Brigham Young University Department of Theatre and Cinematic Arts from 1975–89. He moved to head up the USC drama department in Los Angeles until his death in 1993.
Tad Danielewski and was married three times. First, to Sylvia Daneel who bore him a son, Christopher Danielewski. Second, to Priscilla Decatur Machold who bore two children: a daughter, Anne Danielewski (the musician Poe), and a son, Mark, a novelist (House of Leaves and Only Revolutions). His third wife was named Lillian.
- Tad Danielewski at the Internet Movie Database
- Tad Danielewski at the University of Wisconsin's Actors Studio audio collection
- Article in The New York Times, 13 January 1993
- Article in the Los Angeles Times, 13 January 1993
- Info. regarding Tad Danielewski and Sylvia Daneel (born as Sylwia Jadwiga Łakomska) from the New York City Public Library for the Performing Arts at Lincoln Center (clippings files/3rd floor)
- "Tad Danielewski, An Acting Teacher And a Director, 71, Dead". The New York Times. January 13, 1993.
- "About Poe". The Official Poe Music Network. Retrieved November 1, 2012.
- "Official Only Revolutions website". Retrieved November 1, 2012.
- "Tad Z. Danielewski; Founder of Actors Workshop". Los Angeles Times. January 13, 1993.