Mary Ann Cohen (born July 16, 1943 in Albuquerque, New Mexico) is an American lawyer who serves as a senior judge of the United States Tax Court. Cohen attended public schools in Los Angeles before earning a Bachelor of Science from the University of California at Los Angeles in 1964 and a Juris Doctor from the University of Southern California Law School in 1967. From 1959 to 1966 she was a bookkeeper and later secretary for two family owned businesses in Los Angeles. From 1966 to 1967 she was a legal researcher for multiple lawyers based in Los Angeles. Cohen then practiced law in Los Angeles with the law firm of Abbott & Cohen from 1967 to 1982.