Cecil Mary Leslie (1900–1980) was an engraver, portrait painter, sculptor and illustrator. She studied at the Royal Academy Schools, and exhibited from 1923 until 1939 at the Royal Academy; the Society of Women Artists; the Royal Glasgow Institute of the Fine Arts; the Walker Art Gallery, Liverpool; the New English Art Club; the Royal Society of British Artists; the Royal Cambrian Academy of Art; and the Royal Scottish Academy. Cecil Mary Leslie also exhibited in the United States, France, Czechoslovakia, the Netherlands, Australia and New Zealand. Her home was in Blakeney, Norfolk, England.
Cecil Leslie illustrated the Puffin editions of the classic Heidi (1956) and E. Nesbit's The Story of the Treasure Seekers (1958), The Wouldbegoods (1958) and The Enchanted Castle (1964). She also illustrated many of Pauline Clarke's books, including the Carnegie Medal winner, The Twelve and the Genii, and several other children's books by Rose Fyleman and Alison Uttley, among others.