Patricia Paz Maria Medina was born on July 19, 1919 in Liverpool, England to a Spanish father and an English mother. She began acting as a teenager in the late 1930s and worked her way up to leading roles in the mid-1940s, then left for Hollywood. Medina teamed up with British actor Louis Hayward and they appeared together in Fortunes of Captain Blood (1950), The Lady and the Bandit (1951), Lady in the Iron Mask (1952) and Captain Pirate (1952). Voluptuous and exotic-looking, Medina was often typecast in period melodramas such as The Black Knight (1954). Two of her more notable films were William Witney's Stranger at My Door (1956) and Orson Welles's Mr. Arkadin (1955), a follow-up of The Third Man (1949), based on the radio series "The Lives of Harry Lime". Although prolific during the early 1950s, her film career faded away by the end of the decade, leading to stage and television roles.

Medina appeared as Margarita Cortazar in four episodes of Walt Disney's Zorro (1957), and as Diana Coulter in two episodes of Richard Boone's Have Gun - Will Travel (1957). She returned to the screen in Robert Aldrich's adaptation of the lesbian-themed drama The Killing of Sister George (1968). She and her husband, American actor Joseph Cotten, toured together in several plays and on Broadway in the murder mystery, "Calculated Risk". Her appearances on television include episodes of Bonanza (1959) titled "The Spanish Grant" and The Alfred Hitchcock Hour (1962) titled "See the Monkey Dance". She played Harriet Balfour in an episode of Perry Mason (1957) titled "The Case of the Lucky Loser", and as Lucia Belmont in an episode of The Man from U.N.C.L.E. (1964) titled "The Foxes and Hounds Affair".

Patricia Medina retired from acting in 1978 after 40 years in the motion picture industry. She died at age 92 of natural causes on April 28, 2012 in Los Angeles, California. She was interred at Blandford Cemetery in Petersburg, Virginia, alongside Cotten.