Marcia Lucas, the Oscar-winning film editor who helped shape Star Wars into one of the most famous movies in Hollywood history, has died at 80.

The trailblazing editor, once known inside the industry as George Lucas’ “secret weapon,” died Wednesday at her vacation home in Rancho Mirage, California, after being diagnosed with cancer, her family said.

Her death marks the loss of one of the most important behind-the-scenes figures in American film — a woman whose fingerprints were on some of the biggest and most influential movies of the 1970s and early 1980s.

Marcia Lucas was best known for her work on the original Star Wars, the 1977 sci-fi smash directed by her then-husband, George Lucas. The movie became a cultural earthquake, changing Hollywood forever and launching one of the most beloved franchises in movie history.

But fans may not realize just how much Marcia helped bring that galaxy far, far away to life.

She won the Academy Award for Best Film Editing for Star Wars, sharing the Oscar with Richard Chew and Paul Hirsch. Her work helped give the movie its pace, heart, tension and emotional punch — turning a risky space adventure into a blockbuster that stunned audiences around the world.

Marcia and George Lucas were married from 1969 to 1983, and during their years together, she played a major creative role in his early career. She co-edited American Graffiti, the nostalgic coming-of-age hit that helped make George Lucas a major force in Hollywood before Star Wars.

She later returned to the Star Wars universe as an editor on Return of the Jedi, the 1983 film that closed out the original trilogy.

But her résumé went far beyond lightsabers and X-wings.

Marcia Lucas also worked closely with Martin Scorsese during one of the most legendary stretches of his career. She served as an editor on Alice Doesn’t Live Here Anymore, Taxi Driver and New York, New York.

That means she had a hand in shaping not just Star Wars, but some of the grittiest, most unforgettable films of the 1970s.

Her family remembered her as far more than a Hollywood legend.

“Marcia will be remembered as a brilliant storyteller, a trailblazer for women in film, a loving mother and grandmother, a loyal friend whose humor and sparkle filled every room she entered,” the family said in a statement.

They added that her influence on film was “indelible,” but said those closest to her would remember how she made life feel “more vivid, more beautiful, more fun, and more full of love.”

Her relatives also praised her rare gift for finding “the truth of a scene” and bringing “heart, momentum, and clarity to the screen.”

Lucasfilm also paid tribute after her death, saying the company was “deeply saddened to learn of the passing of Marcia Lucas.”

For decades, Marcia’s role in the success of Star Wars was often discussed by fans and film historians who believed her editing instincts helped save and strengthen the movie. While George Lucas became the public face of the franchise, Marcia’s work remained a major part of the original film’s magic.

She helped turn chaotic footage, emotional character moments and massive action sequences into a movie that moved fast, felt human and left audiences cheering.

In an industry where editors often work in the shadows, Marcia Lucas became proof that the person in the cutting room can change movie history.

Her work helped define an era. Her influence helped shape a franchise. And her legacy will live on every time fans return to that opening crawl and hear the blast of John Williams’ score.