She emigrated to the UK just before the onset of World War II and studied at the Royal College of Music, becoming friends with Benjamin Britten and John Amis. With Fanny Waterman, she founded the Leeds International Piano Competition and collaborated on the piano tutor Piano Lessons. Marion played professionally, in a duo with Catherine Shanks.
In 1949 she married George Lascelles, an opera administrator and Seventh Earl of Harewood, becoming Countess of Harewood. After divorcing in 1967, she married British politician and leader of the Liberal Party, Jeremy Thorpe, in 1973.
Marion Thorpe died on 6 March 2014, aged eighty-seven.