Sarah Walker CBE (born 11 March 1943) is a British mezzo-soprano.
Walker was born in Cheltenham, Gloucestershire. She studied at the Royal College of Music from 1961 to 1965, initially as a violinist and cellist, and went on to study singing with Vera Rozsa. She has appeared in numerous opera performances and is also known as a concert soloist and recitalist.
Walker's operatic debut was in 1969, as Ottavia in Kent Opera's production of L'incoronazione di Poppea. She has also appeared in Britain with Glyndebourne Festival Opera, The Royal Opera, English National Opera, Scottish Opera, and abroad at The Metropolitan Opera (New York City), Lyric Opera of Chicago, San Francisco Opera, La Monnaie (Brussels) and the Vienna State Opera.
Notable roles have included the title-roles in Gloriana and Maria Stuarda, Dido in Les Troyens and Baba the Turk in The Rake's Progress. She recorded the challenging Voices under the direction of its composer, Hans Werner Henze, in 1978.