"A legend, a friend, a mentor, an icon, and wildly funny. One of a kind. RIP #JoanRivers" tweeted Kathy Griffin, a fellow comedian who is also known for her confessional and controversial humour.
"Joan Rivers will always be a pioneer. She paved the way for a lot of comedians. I’m very sad she’s gone." tweeted Ellen DeGeneres, while E!'s Fashion Police twitter account, added: "We're very sad to share that Joan Rivers has passed away. Our hearts go out to her family."
Joan Rivers will always be a pioneer. She paved the way for a lot of comedians. I’m very sad she’s gone. pic.twitter.com/i1uE9fyHMh— Ellen DeGeneres (@TheEllenShow) September 4, 2014
— Kathy Griffin (@kathygriffin) September 4, 2014
She was surrounded by friends and family, and in a statement her daughter Melissa said: "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.
Known for her catchphrase, "can we talk?", Joan was an actress, writer, producer, and TV host of the incredibly successful Fashion Police.
Her co-host George Kotsiopoulous tweeted: "Rest in peace @Joan_Rivers. Thank you for changing my life. I will miss you so much."
Joan was a pioneer, with her confrontational, confessional, and often aggressive comedic style riling many but providing a pathway for other female stand-ups to emerge and go toe-to-toe with male comics.
Female comics who were influenced by her include Lena Dunham and Sarah Silverman, and both tweeted their condolences on Thursday, with Lena writing: "Watching Joan Rivers do standup at age 81 was incredible: athletic, jaw-dropping, terrifying, essential. It never stopped. Neither will she.
"I told Maron I'd have a zinger when Joan died. But I didn't think she ever would. She felt eternal, and anyway, zingers are her territory. That being said, Joan is gone but a piece of her lives on: her nose, because it's made of polyurethane."
Some celebrities also remembered warmly times when Joan had put her wit and sharp tongue to use as a host on Fashion Police.
Pitch Perfect actress Anna Kendrick wrote: "RIP Joan Rivers. Being publicly told that my dress is hideous will never feel quite as awesome. You will be truly missed."
Rest in peace @Joan_Rivers. Thank you for changing my life. I will miss you so much.— George Kotsiopoulos (@GeorgeKotsi) September 4, 2014
Watching Joan Rivers do standup at age 81 was incredible: athletic, jaw-dropping, terrifying, essential. It never stopped. Neither will she.— Lena Dunham (@lenadunham) September 4, 2014
My friend Joan Rivers has passed away once again to quote Billy Crystal... There are no words. Bon Voyage Joan 😢— Whoopi Goldberg (@WhoopiGoldberg) September 4, 2014
RIP the mighty Joan Rivers. Funny & fearless. Truly one of a kind.— Ricky Gervais (@rickygervais) September 4, 2014
We've lost a true legend today and an amazing woman - a pioneer. She opened up the arena for women in comedy....— Sharon Osbourne (@MrsSOsbourne) September 4, 2014
Joan Rivers has died. What a sad ending to a brilliant and tragi-comic life; one of the bravest, and funniest of all.— Bette Midler (@BetteMidler) September 4, 2014
RIP GODDESS: Hail Hail, a GENIUS has vacated this realm: Joan Rivers has died.— Roseanne Barr (@therealroseanne) September 4, 2014
And in addition to being a trailblazer the great Joan always smelled good.Thanks for taking my challenge. I still owe you one. RIP x,sj— Sarah Jessica Parker (@SJP) September 4, 2014
RIP Joan Rivers. Being publicly told that my dress is hideous will never feel quite as awesome. You will be truly missed.— Anna Kendrick (@AnnaKendrick47) September 4, 2014