Thomas Marvin Hatley (April 3, 1905 – August 23, 1986), professionally known simply as Marvin Hatley, was an American film composer and musical director, best known for his work for the Hal Roach studio from 1929 until 1940. In 1939, Hatley was fired from the Roach studio. At the insistence of Stan Laurel, however, he did return to score one final Laurel & Hardy film, Saps at Sea. Hatley went on to become a lounge pianist, and often remarked that he earned more money in that career than during his days at the Roach studio.