Donald M. Marshman, Jr., credited as D.M. Marshman, is an American screenwriter known mainly for his contribution to the film script for Sunset Boulevard.
Marshman was educated at Andover and Yale, receiving his B.A. in 1945. Originally hired as an editorial researcher at Life Magazine, he eventually became the magazineâ€™s movie editor before moving to Time Magazine, where he was the film critic.
In 1948, Marshman was recruited by Charles Brackett and Billy Wilder to help write the screenplay of Sunset Boulevard. He suggested that a gigolo be introduced to the story as a romantic interest for the heroine. Characteristics of the main character can be attributed to Marshman, such as name similarity, personality, and identical birthday. He shared a screenwriting credit with Wilder and Brackett. The three won an Academy Award for Writing Original Screenplay. Marshman has only one other film to his credit, a 1953 production titled Taxi.
He chose to return to the East Coast in 1953, where he pursued a career in advertising for Young & Rubicam and other agencies, including one he started himself. From 1974 to 1979, he conducted a fund-raising campaign for Yale University, and has spent the years since as a freelance consultant, writing speeches for corporate CEOs, and doing other business writing.