Alley, best known for her role as Rebecca in Cheers, died surrounded by her family after treatment at the Moffitt Cancer Center in Florida, her family announced on Monday evening.
“Our mother’s zest and passion for life, her children, grandchildren and her many animals, not to mention her eternal joy of creating, were unparalleled and leave us inspired to live life to the fullest just as she did,” her family wrote on Twitter.
In the statement, her children True and Lillie Parker, said the actress had “only recently discovered” she was suffering from the disease.
“She was surrounded by her closest family and fought with great strength, leaving us with a certainty of her never-ending joy of living and whatever adventures lie ahead,” said the statement shared on Alley’s social media.
Her family also thanked the doctors and staff at the Moffitt Cancer Center, which is based in Tampa.
Alley became famous for her role as the bar manager Rebecca Howe in the long-running NBC sitcom opposite Ted Danson, but also had a successful movie career, starring in Look Who’s Talking and its sequels with John Travolta.
Travolta, a fellow Scientologist, took to Instagram to honour his former co-star and friend.
“Kirstie was one of the most special relationships I’ve ever had,” he posted to Instagram. “I love you Kirstie. I know we will see each other again.”
Alley won a Golden Globe and Emmy in 1991 for her role in Cheers and an Emmy for the 1994 made-for-TV film David’s Mother. She joined Cheers in 1987 and went on to appear in 147 episodes until it ended in 1993.
Kelsey Grammer, who played Dr Frasier Crane on the show, paid his own tribute to his late co-star.
“I always believed grief for a public figure is a private matter, but I will say I loved her,” he told Variety in a statement.
Kansas-born Alley shared her children with ex-husband Parker Stevenson, to whom she was married from 1983 until 1997. She was also married to Bob Alley from 1970 until 1977.
In recent years, Alley claimed to have been “blackballed” by Hollywood because of her support for Donald Trump, despite voting twice for Barack Obama.
She told Fox News host Tucker Carlson in May 2021 that she had been advised in 2015 to keep her political opinions to herself, and that her career had suffered for not doing so.
“People go, ‘You’re so brave.’ I go, ‘No, I think I’m stupid’,” she said. “It’s so strange to me because artists are free-thinkers, for the most part.
“You can be cooking meth and sleeping with hookers, as long as apparently you didn’t vote for Trump. I feel like I’m in The Twilight Zone a bit, with the whole concept of it.”
She told the right-wing host that she had lost celebrity followers on Twitter because of her political leaning.
She also claimed that many celebrities had unfollowed her on Twitter for sharing her political views, adding: “I’m going, ‘I’m the same person. I’m the girl who voted for Obama twice… You liked me when I voted for Obama and now you’re this?’ It’s made me have to rethink, weirdly, my whole friendships.”
Following Alley’s interview, Trump shared a statement calling the Emmy winner “strong and smart” and “a great actress”.
“Just got a very kind acknowledgement,” Alley tweeted as she reposted the former president’s words. “Thank you Sir, I wish you were still on Twitter... as you should be.”