Son Nick Reynolds said his father died on Thursday after a brief illness.
Reynolds was part of a gang that stole 2.6 million pounds from a Glasgow-to-London mail train in 1963 - worth more than 40 million pounds ($60 million) today, and then Britain's biggest robbery.
Reynolds evaded capture for five years but was arrested in 1968, and sentenced to 25 years in jail. He was released a decade later and produced occasional journalism and well-regarded memoirs.
Most of the other gang members also were soon rounded up.
One, Ronnie Biggs, escaped from prison in 1965, and spent decades as a fugitive in Brazil before returning to Britain in 2001.