Ivy St. Helier (1886, St Helier, Jersey – 1971, London, England) was a British stage actress, composer and lyricist.
On the stage, St. Helier played Manon la Crevette in the original production of Noel Coward's operetta Bitter Sweet (1929), a role she reprised in the 1933 film version. She also starred in Coward's revue Words and Music As a lyricist, she wrote songs for The Street Singer to a score by Frederick Lonsdale, and wrote additional songs for The Blue Train, the London musical by Reginald Arkell, Dion Titheradge and Robert Stolz.
She made five films, including Laurence Olivier's Henry V (1944) and London Belongs to Me (1948).