She was 60 years old.
"It is with a very deep sadness that Billie Lourd confirms that her beloved mother, Carrie Fisher, passed away at 8:55 this morning," Halls said in a statement. "She was loved by the world, and she will be missed profoundly."
And Harrison Ford, who played Han Solo in "Stars Wars," said in a statement Tuesday, "Carrie was one of a kind … brilliant, original. Funny and emotionally fearless. She lived her life, bravely ... My thoughts are with her daughter Billie, her mother Debbie, her brother Todd and her many friends. We will all miss her."
Fisher was rushed to the hospital after going into into cardiac arrest while aboard a flight from London to Los Angeles on Friday.
Just last month, in an interview with Rolling Stone magazine, Fisher was asked if she feared death.
"No. I fear dying," she said. "Anything with pain associated with it, I don't like. I've been there for a couple of people when they were dying; it didn't look like fun. But if I was gonna do it, I'd want someone like me around. And I will be there!"
Earlier in the Rolling Stone interview, she said, "I'm not going to enjoy dying, but there's not much prep for that."
She was a top Hollywood script doctor, polishing other writers' screenplays. Among the movies she worked on: "Hook," "Lethal Weapon 3" and "Outbreak."
Fisher, who struggled with drug addiction and bipolar disorder, received an Emmy nod for her work in an episode of "30 Rock," and she mounted one-woman plays and published more books, including 2016's "The Princess Diarist."
Her acting career was revitalized with her return as Leia in 2015's "The Force Awakens," in which we learn that Leia and Han Solo have split up and that their son Ben, aka Kylo Ren, has turned to the dark side of the Force.
Fisher is survived by her daughter, mother, brother and half-sisters Joely Fisher and Tricia Leigh Fisher.
ABC News' Lesley Messer and David Caplan contributed to this report.