"One of the last great broads in our business - Jeanne Cooper, Mom - is now stirring up trouble in great beyond," her family said in a statement.
For 40 years, Cooper played grande dame Katherine Chancellor on the daytime drama "The Young and the Restless."
Cooper had been in and out of a local hospital recently due to an undisclosed illness. Her son, actor Corbin Bernsen, confirmed his mother's death, Tweeting, "Mom passed this morning. She was in peace and without fear."
Born in Kern County in the town of Taft in 1928, Cooper attended the College of the Pacific and performed in local theater productions.
"I have a passion for what I do. Acting is not just a job; acting is a way of life," Cooper once said in an interview.
While Cooper spent the last 40 years on "The Young and the Restless," she began her career in the early 1950s with the film "The Redhead from Wyoming" starring Maureen O'Hara. Other film credits include 1968's "The Boston Strangler" with Tony Curtis and 1967's "Tony Rome" with Frank Sinatra.
Cooper joined the daytime serial six months after its March 1973 debut, staking claim to the title of longest-tenured cast member. The role earned her 11 Daytime Emmy nominations and a trophy for best actress in a drama series in 2008.
In 1984, Cooper's real-life facelift was televised on the show as her character underwent the surgery at the same time, and had no regrets about it.
"It opened up reconstructive surgery for so many people, youngsters getting things done," she said. "To this day, people will come up to me and say, 'Thank you so much for doing that. My mom or I had something done, and not just cosmetic surgery.' That was an incredible experience in my life."
The Associated Press contributed to this report.