The actress played Melanie Hamilton Wilkes, who squared off with Scarlett O'Hara to gain the affection of Ashley Wilkes, played by Leslie Howard.

The 1939 movie became one of the icons in cinema ... played and replayed every year in movie theaters across the country. The movie has drawn constant and increased criticism over glorifying the South during the Civil War, and recently, when HBO Max released it on its streaming service, it provided context at the beginning.

Olivia starred in a number of other movies, including "The Adventures of Robin Hood." She won Oscars for her performances in "To Each His Own" and "The Heiress."

Olivia was also embroiled in a long-standing Hollywood feud with her sister, actress Joan Fontaine, and gossip mags couldn't get enough of it.

Olivia was angry over Ryan Murphy's miniseries, "Feud: Bette and Joan," because of the way she was portrayed, and sued FX but lost.

She also was important in putting an end to the archaic studio system in Hollywood. When she was under a long-term contract with Warner Bros., she put her foot down, refusing certain roles, which got her benched more than once. She ended up suing Warner Bros., saying the studio system amounted to "peonage," and the judge agreed and freed her from her remaining obligations under her contract.

The legal fight changed the balance of power in Hollywood, and actors were able to negotiate better contracts as a result.

Olivia has lived in Paris since 1960 and rarely attended public functions. There was a splashy party in Hollywood for her 90th birthday -- thrown by the Academy of Motion Picture Arts & Sciences -- and she showed up.

And, check out the cool pic ... Olivia last year -- 103 years old -- riding a bike.

Olivia was 104.