Russell's daughter-in-law Etta Waterfield said the actress died on Monday at her home in Santa Maria of a respiratory-related illness.
Hughes, the eccentric billionaire, cast Russell in his sexy, and controversial, 1941 Western The Outlaw, turning her into an overnight star.
She would go on to appear opposite such leading men as Frank Sinatra and Bob Hope, as well as fellow actress Marilyn Monroe.
Until her health began to decline a few weeks ago, Ms Waterfield said she remained active singing and working for various causes.
With her sultry look and glowing sexuality, Russell became a star before she was ever seen by a wide movie audience. The Hughes publicity mill ground out photos of the beauty in low-cut costumes and swim suits, and she became famous, especially as a pin-up for Second World War GIs.
By that time she had become a box-office star by starring with Bob Hope in the 1948 hit comedy-Western The Paleface.
Although her look and her hourglass figure made her the subject of numerous nightclub jokes, unlike Monroe, Rita Hayworth and other pin-up queens of the era, Russell was untouched by scandal in her personal life. During her Hollywood career she was married to star UCLA and pro football quarterback Bob Waterfield.
After her movie career faded, she became the leader of the Hollywood Christian Group - a cluster of film people who gathered for Bible study and good works. After experiencing problems in adopting her three children, she founded World Adoption International Agency, which has helped facilitate adoptions of more than 50,000 children from overseas.
