Her daughter Billie Lourd said the actress passed away on Tuesday morning after being taken ill travelling from London to Los Angeles, reports telegraph.co.uk.
She is survived by her mother, the veteran Hollywood star Debbie Reynolds, who has been by her side along with her close family over Christmas.
Post her cardiac arrest, fans of Fisher had hoped for her recovery following reports that she was "stable", with her uncle disclosing the family had believed there would be a positive outcome.
But a spokesman for the family said: "It is with a very deep sadness that Billie Lourd confirms that her beloved mother Carrie Fisher passed away at 8.55 a.m. She was loved by the world and she will be missed profoundly. Our entire family thanks you for your thoughts and prayers."
"Thank you to everyone who has embraced the gifts and talents of my beloved and amazing daughter. I am grateful for your thoughts and prayers that are now guiding her to her next stop. Love Carrie's Mother," said 84-year-old Reynolds.
Fisher had been in hospital since December 23, when she fell ill on a United Airlines flight.
Said to be initially "unresponsive", she was rushed to a hospital in Los Angeles where she was treated in an intensive care unit but did not regain consciousness.
Four days later, after spending Christmas in hospital, Fisher's daughter confirmed she had died.
Her uncle Bill Reynolds, brother of Debbie, said: "The family all had hope. That's what the doctors told us, that she would recover. On Christmas Eve we all had dinner together at my sister's house and said prayers. Everything looked positive and everyone seemed pretty upbeat."
He added: "We don't have enough details yet. But the family is all gathering. We all loved her and no one expected anything like this."
Fisher was expected to make her final appearance on screen as General Leia Organa, after completing filming on "Star Wars: Episode VIII."
Her death has already sparked speculation over how the franchise would proceed without her.
She had recently been undertaking a book tour for her autobiography, "The Princess Diarist", making headlines with her mischievous confessions about her youthful affair with Harrison Ford.