Rebecca Helferich Clarke (27 August 1886 – 13 October 1979) was a British-American classical composer and violist. Internationally renowned as a viola virtuoso, she also became one of the first female professional orchestral players. Born in England (of a German mother and an American father), Rebecca Clarke claimed both British and American nationalities and spent substantial periods of her long life in the United States, where she permanently settled after World War II. She was born in Harrow and studied at the Royal Academy of Music and Royal College of Music in London. Stranded in the United States at the outbreak of World War II, she married composer and pianist James Friskin in 1944. Clarke died at her home in New York at the age of 93.