Nitish Mishra, son of the three-time Chief Minister, told IANS that his father, who had been ailing for some time, passed away around 9.45 a.m.
Mishra had been reportedly suffering from multiple ailments and was receiving treatment at a Delhi hospital.
Once a powerful figure for the Congress in Bihar politics, Mishra first became Chief Minister in 1975 and then returned to office in 1980 and 1989 before Lalu Prasad succeeded him.
Mishra was also a former Union cabinet Minister. His brother, L.N. Mishra, had been assassinated.
Congress interim President Sonia Gandhi condoled the death of Jagannath Mishra, saying he always stood for the interests of the deprived and marginalised minorities in society.
“He will be remembered for a long time to come,” she said in a statement.
In 2013, a special CBI court in Ranchi convicted Jagannath Mishra along with 44 others in the fodder scam.