Rendell suffered a stroke in January and had been in a critical condition in hospital.
In a statement, Penguin Random House said: "We are devastated by the loss of one of our best-loved authors."
"We will miss her enormously," it said.
Gail Rebuck, chair of Penguin Random House UK, said: "Ruth was much admired by the whole publishing industry for her brilliant body of work.
"An insightful and elegant observer of society, many of her award-winning thrillers and psychological murder mysteries highlighted the causes she cared so deeply about," she said.
Her fictional creation, the sensitive Chief Inspector Reginald Wexford, featured in her first novel "From Doon to Death" (1964) and throughout her career.