George Oppenheimer had a prolific career as a playwright, screenwriter, and drama critic. His first job was as advertising publicity manager for the publisher Alfred A. Knopf. A jeweller's son, Oppenheimer moved to Hollywood in 1933 where he was contracted by the writing team of George S. Kaufman and Robert E. Sherwood to complete the screenplay of Samuel Goldwyn's spoof comedy Roman Scandals (1933). Kaufman and Sherwood had concocted the original story but decided to leave the project because of star Eddie Cantor's continued micro-management of their script. For the remainder of the decade Oppenheimer worked at MGM, where he was often employed as a script doctor, ironing out incongruities and improving the work of his fellow writers. He had a hand in several major box-office hits, including Libeled Lady (1936), A Day at the Races (1937) and A Yank at Oxford (1938).

After wartime service with South-East Asia Command (First Motion Picture Unit) in India as writer, producer and director of training films and documentaries, Oppenheimer resumed his work in Hollywood, co-writing Adventures of Don Juan (1948) and scripting twenty-five episodes of the popular comedy series Topper (1953). In 1955, he forsook the screen for a position as drama critic for Newsday, based in New York. From 1970 to 1972, he held a position as president of the New York Drama Critics Circle.