1A spokeswoman said Cooper's family told the network of her death.
Cooper played grande dame Katherine Chancellor on The Young and the Restless for nearly four decades.
Her son, actor Corbin Bernsen, tweeted in April that his mother faced an "uphill battle" for an undisclosed illness. On May 8, he tweeted, "Mom passed this morning. She was in peace and without fear. U all have been incredible in your love. In her name share it 2 day with others."
Cooper's role on The Young and the Restless earned her repeated Daytime Emmy Award nominations and a trophy for best actress in a drama series in 2008.
-- The Associated Press