Mary Ellis (born May Belle Elsas; June 15, 1897 – January 30, 2003) was an American actress and singer who spent most of her career in Britain. Trained as a lyric soprano, she began performing at the Metropolitan Opera where she created the role of Genovieffa in the world premiere of Giacomo Puccini's Suor Angelica in 1918. In 1924, she originated the title role in Rudolf Friml's operetta Rose-Marie at Broadway's Imperial Theatre. Other Broadway parts included Shakespeare roles such as Kate in The Taming of the Shrew.
After immigrating to England in 1930, Ellis performed in musicals in London's West End. She achieved enduring fame in the leading roles of the original productions of two Ivor Novello pieces: Glamorous Night (1935) and The Dancing Years (1938). After performing welfare work in hospitals during World War II, she returned to acting in London in plays by Noël Coward, Terence Rattigan and Shakespeare. She also worked in radio, television and film; including in The 3 Worlds of Gulliver in 1960. Her career spanned more than half a century of her 105-year-long life.