Rachel Kempson was born in Dartmouth, England, and trained at RADA before joining the Royal Shakespeare Company. She married Michael Redgrave in 1935, and appeared with him many times on stage. Although overshadowed by the rest of the family, she appeared many times on film and television, notably in The Captive Heart (1946), Tom Jones (1963), Out of Africa (1985), and the television series, The Jewel in the Crown (1984).
She died at her daughter's home in Millbrook, New York.