Malimath was undergoing treatment for the last three weeks for viral infection and significant weakness, Manipal Hospitals Chairman Dr H Sudarshan Ballal said.
He was subsequently moved to ICU and breathed his last late last night, Ballal said.
He is survived by one son and four daughters.
Malimath had served as Chairman of the Central Administrative Tribunal and as a Member of the National Human Rights Commission. He also headed the Committee on Reform of Criminal Justice System in India, and was the UN representative to monitor human rights enforcement in Nigeria and Sri Lanka.
He was appointed as Judge of the High Court of Karnataka in 1970 and its Chief Justice in 1984. He was later transferred to Kerala as Chief Justice in 1985.
Recipient of many state and national awards, Malimath was also an International Observer to oversee the referendum in Sri Lanka.