The acid-tongued comic who broke the male stranglehold on late-night talk shows had been in hospital since last week.
Comedian Joan Rivers has died in New York at the age of 81, her daughter has confirmed.
The notoriously sharp-tongued comic had stopped breathing and gone into cardiac arrest at Mount Sinai Hospital in Manhattan last week while undergoing an operation on her vocal chords.
She was put on a life support system until the day before her death when she was moved out of intensive care and "kept comfortable", but her condition deteriorated.
In a statement, her daughter Melissa Rivers said: "It is with great sadness that I announce the death of my mother, Joan Rivers.
"She passed peacefully at 1.17pm, surrounded by family and close friends."
She added: "My mother's greatest joy in life was to make people laugh.
"Although that is difficult to do right now, I know her final wish would be that we return to laughing soon."
Ms Rivers was known for a long television career, during which time she broke the 'glass ceiling' by becoming the first female host of a late night chat show.
More recently she was host of E!'s Fashion Police, which involved her talking about the unfortunate red carpet choices of Hollywood celebrities.
Her friend Jeanne Wolf, speaking to Sky News Tonight, said that her relatives must have known she was close to death as they made preparations.
"It's very sad. I've really been waiting for this news for days but I was hoping I wouldn't get it and when I heard the words 'she is dead' it really hit me in the heart.
"Even the people who didn't approve of her or fought her back will miss her because she was so brave and so quick and smart and talented and funny.
"I keep trying to think of jokes, which is a terrible thing to say, but it's exactly what Joan would be doing if she was in the room right now.
"I think she was very insecure about her appearance. She never felt pretty.
"Cindy Adams her dear friend said they brought in a hairdresser, and a make up artist. They must have known she was near death and dressed her up and that was understanding her. She really was a total fighter.
"It was impossible for a woman to be taken seriously as a comedian. She fought to get those bookings when she thought 'they are not going to hire me any more'. She said 'I'll show them...'"
As well as her daughter, she had one grandson, Cooper. Her husband, Edgar Rosenberg, died in 1987.
Melissa Rivers added: "Cooper and I have found ourselves humbled by the outpouring of love, support, and prayers we have received from around the world. They have been heard and appreciated."
