Reginald Marsh (14 March 1898 - 3 July 1954) was an American painter, born in Paris, most notable for his detailed depictions of life in New York City in the 1920's and 1930's. He painted using egg tempera, a forgotten medium revived in the mid-twentieth century. He also produced many watercolors, oil paintings, Chinese ink drawings, and a number of lithographs and etchings.

Marsh attended the Lawrenceville School and graduated in 1920 from Yale University, he then worked as a freelance illustrator, then for the New York Daily News and for The New Yorker. He also submitted illustrations to the New Masses

Marsh was impressed by the 'old master' paintings he saw on a 1926 European trip. He returned with a desire to utilize the principles he felt were evident in the art of the Renaissance painters, particularly the practice of taking notes from observation of human subjects in their environments. Marsh then studied under Kenneth Hayes Miller, John Sloan and George Luks at the Art Students League of New York, and chose to do fewer commercial assignments.

His most famous paintings are "Why Not Use the 'L'?" (painted 1930, now at the Whitney Museum of American Art); "In 14th Street" (painted 1934, now at the Museum of Modern Art, New York City); "High Yaller" (painted 1936, now in a private collection); "Pip and Flip" (painted 1932, at the Terra Museum of Art, Chicago, Il.); and Tattoo Haircut-Shave (painted 1932, at the Art Institute of Chicago). In his etchings, for example "Bread Line - No On Has Starved," (1932), Marsh concentrated in a journalistic style somewhat reminiscent of the etchings of Goya in which tragic human events are shown. Though apolitical, Marsh was nonetheless drawn toward subjects that emphasized the social pressures and traumas of his time, whether by featuring the dispossessed of the American depression of the 1930s, or by exploring the glamorous advertising images used to sell products to women.

He is credited with giving famous American artist Roy Lichtenstein his first art tutelage through a summer camp run by the Art Students League of New York.

Reginald Marsh (17 September 1926 - 9 February 2001) was an English actor who is best remembered for starring in many British sitcoms from the 1970s onwards.

Reginald died at his home in Ryde, Isle of Wight aged 74, where he had lived since the late eighties. While there he did a great deal of work for local charities, especially Haylands Farm, a project for young people with learning difficulties, and the local branch of MENCAP. He is survived by his wife, former actress Rosemary Murray, twin daughters, Rebecca and Alison, sons Adam and Alexander, and son John and daughter Kate from his first marriage.