Fawcett, whose celebrity overshadowed her ability as a serious actress, was diagnosed with a rare cancer in 2006. She died at St. John's Health Center in Santa Monica, said Paul Bloch, her publicist.
Three months after she was declared cancer-free in 2007, doctors at UCLA Medical Center told her the cancer had returned and spread to her liver, and she repeatedly sought experimental treatment in Germany.
Actor Ryan O'Neal, her longtime companion, called her cancer fight "long and brave" and said her family and friends took comfort in "the knowledge that her life brought joy to so many people around the world."
Kate Jackson called her "Charlie's Angels" costar "an inspiration" who "showed immense courage and grace throughout her illness."
"When I think of Farrah, I will remember her kindness, her cutting dry wit and, of course, her beautiful smile," Jackson said in a statement.
Another "Charlie's Angels" costar, Jaclyn Smith, said in a statement, "Farrah had courage, she had strength, and she had faith. And now she has peace as she rests with the real angels."
As an actress, Fawcett was initially dismissed for her role as Jill Munroe in "Charlie's Angels," one of the "jiggle" series on ABC-TV in the late 1970s.
But she transformed her career and some popular perceptions in 1984 with "The Burning Bed," a television movie about a battered wife that brought her the first of three Emmy nominations. She further established herself as an actress in the play and later feature film “Extremities,” about a rape victim who takes revenge on her attacker.
Robert Greenwald, who directed "The Burning Bed," told The Times on Thursday, "She was incredibly gutsy, courageous and a risk-taker. She had this wonderful beauty, this very successful career and, unlike many people, she used it to open doors and take big chances."
Yet for many, the poster of her wearing a wet, one-piece swimsuit and a blinding smile endured.
"If you were to list 10 images that are evocative of American pop culture, Farrah Fawcett would be one of them," Robert Thompson, a professor of television and popular culture at Syracuse University, told The Times. "That poster became one of the defining images of the 1970s."
Fawcett was part of a new generation of celebrities whose fame was fueled by heightened coverage of their ongoing personal dramas, Thompson said.
She had many: a failed marriage to actor Lee Majors; a stormy, long-term relationship with O'Neal; a son who fought drug addiction; a writer-director boyfriend, James Orr, who was convicted of assaulting her; a Playboy video that featured her using her naked body as a paintbrush; and a spacey 1997 appearance on David Letterman's late-night TV show that caused critics to question her mental state.
For her part, Fawcett once said all she had to do to get on the cover of People was to "have a new boyfriend or even a new dog," Texas Monthly reported in 1997.
At first, her mane nearly eclipsed her fame.
"Charlie's Angels" showcased the long, feathered tresses that framed her face, launching a national fad of copycat haircuts. Many Fawcettphiles believed the hair had as much to do with the poster's sales as anything, The Times reported in 1977.
Within six months, the poster sold five million copies, outstripping the records of such previous sex symbols as Betty Grable and Marilyn Monroe. It wound up selling a reported 12 million copies.
"You were a real man if you had her poster. She was our pinup girl," Mike O'Meara, a radio show host who was in high school when it came out, told the Baltimore Sun in 2006.