The US actress, 84, had been rushed to hospital with a suspected stroke.
Her son, Todd Fisher, said the stress of his sister's death had been too much for her and in her last words, she had said she wanted to be with Carrie.
US actress Bette Midler said Reynolds was "devoted to her craft" and that her death was "too hard to comprehend".
Actress Debra Messing said Reynolds, her on-screen mother in sitcom Will and Grace had been an "inspiration".
"A legend of course," she wrote in a statement.
"An epitome of clean-cut American optimism, dancing with Gene Kelly as an equal a warrior woman who never stopped working.''
Actor Rip Torn, who worked with Reynolds in her Las Vegas stage show, said: "I was blessed to work with this remarkable woman for 45 almost 50 years. That makes for a very rare bond and unique relationship.
"She was generous to a fault, never caring who got the laugh from the audience. I will always love her."
Veteran comic actress Carol Channing agreed: "She was beautiful and generous. It seems like only yesterday she was having lunch here at the house and we were discussing the possibility of working together in a new show."