William Samuel Cook "Peter" Ellenshaw (24 May 1913 – 12 February 2007) was an English matte designer and special effects creator who worked on many Disney features. Born in London, he moved to America in 1953.

He first worked in matte painting for producer Alexander Korda on such films as Things to Come (1936), and later on such Powell and Pressburger productions as Black Narcissus (1947) assisting his mentor W. (Walter) Percy Day. A few years later, while still based in Europe, he began to work for Hollywood studios. He worked for MGM on Quo Vadis (1951), but his most extensive association was with Walt Disney Studios beginning with their first completely live action feature film, Treasure Island (1950). He went on to work on 20,000 Leagues Under the Sea (1954) and Mary Poppins (1964), for which he won an Academy Award. He retired after his work on The Black Hole (1979), but contributed matte paintings for Dick Tracy (1990). both of which he collaborated with his son Harrison Ellenshaw, also a renowned matte artist and effects designer.

After Peter Ellenshaw retired from the film business, he dedicated his life to his passion for painting. Numerous works were created, of both Disney and non-Disney themed subjects, which have been highly collected. He was named a Disney Legend in 1993.^[1]

• Peter Ellenshaw; Ellenshaw Under Glass - Going to the Matte for Disney
• Mark Cotta Vaz; Craig Barron: The Invisible Art: The Legends of Movie Matte Painting, Chronicle Books, 2002; ISBN 0-8118-3136-1