Jean Merilyn Simmons was born on January 31, 1929 in London, England. The daughter of Charles Simmons and Winifred Loveland. Her father, a physical education teacher who had represented Great Britain in the 1912 Summer Olympics.
During World War II, the Simmons family was evacuated to Winscombe in Somerset.
After the war, she returned to London and enrolled at the Aida Foster School of Dance at the age of 14. She was spotted by the director Val Guest, who cast her in the Margaret Lockwood film Give us the Moon.
Her films include Black Narcissus (1947), Hamlet (1948) Affair with a Stranger (1953), The Actress (1953), Guys and Dolls (1955), The Big Country (1958), Elmer Gantry (1960), Spartacus (1960), The Grass Is Greener (1960), Divorce American Style (1967), Heidi (1968), and The Happy Ending (1969).
In 1950, she married the English actor Stewart Granger and they divorced in 1960. They had one daughter, Tracy Granger. Granger and Simmons appeared together in Adam and Evelyne (1949), Caesar and Cleopatra (1945), Young Bess (1953), and Footsteps in the Fog (1955).
In 1960 she married director Richard Brooks, divorcing in 1977. They had one daughter Kate Brooks. Brooks directed Jean in Elmer Gantry (1960) and The Happy Ending (1969).
Jean Simmons received two Academy Award nominations for Best Actress, one for Hamlet (1948) and one for The Happy Ending (1969).
She won the Golden Globe for Best Musical/Comedy Actress, Guys and Dolls (1956).
In 1983, she received the Emmy for Outstanding Supporting Actress for a Series or Special for her role in The Thorn Birds.
Jean Simmon's final film was Shadows in the Sun (2009).
Jean Simmons passed away on January 22, 2010 at the age of 80 from complications of lung cancer.