Kay Walsh graced the British Cinema of the 1930s and 1940s as a leading lady, before maturing into character roles. She was born Kathleen Walsh in London, England of Irish parentage. She and her sister Peggy were raised in Pimlico by their grandmother. She began her career as a dancer in the chorus of several Andre Charlot revues, before performing solo in New York and Berlin. Kay made her screen debut in Get Your Man (1934) and later appeared in The Luck of the Irish (1936). After appearing as a dancer in the West End show "The Melody that Got Lost", the producer Basil Dean signed her to a contract with Ealing Studios. She starred opposite George Formby in the comedies Keep Fit (1937) and I See Ice! (1938). She met an aspiring film editor David Lean in 1936 and they were married in 1940. She collaborated on several of his films by writing additional dialogue and advising on production and casting.