Schary worked as a writer, director, and producer of motion pictures in Hollywood, California and in 1938 won the Academy Award for Best Story as co-writer of the screenplay for the film, Boys Town. In 1948, he became chief of production at Metro-Goldwyn-Mayer studios and following the 1951 ouster of the studio's longtime head and founder Louis B. Mayer, he became MGM's president, serving until 1956.
Following his departure from MGM, he wrote the Broadway play Sunrise at Campobello that won five Tony Awards and wrote and produced a motion picture of the same name in 1960.
He was an outspoken opponent of the witchhunt for communists conducted by Joseph McCarthy that resulted in the Hollywood Blacklist. A liberal activist he served as National Chairman of the B'nai B'rith's Anti-Defamation League and as New York City Commissioner for Cultural Affairs. To honor his memory, the Anti-Defamation League established the Dore Schary Awards in 1982.
Dore Schary died in 1980 and was interred in the Hebrew Cemetery, West Long Branch, New Jersey.