Among his 25 novels were acclaimed best-sellers including Tinker Tailor Soldier Spy, The Spy Who Came In From The Cold, and The Night Manager.
Cornwell drew on his experience serving with the British intelligence services including MI6 during the Cold War in his writing.
His literary agent Jonny Geller, of Curtis Brown, said in a statement: “His like will never be seen again, and his loss will be felt by every book lover, everyone interested in the human condition.
“We have lost a great figure of English literature, a man of great wit, kindness, humour and intelligence.
“I have lost a friend, a mentor and an inspiration.”
Born in 1931, Cornwell was educated at the universities of Bern, in Switzerland, and Oxford, before embarking on his undercover intelligence career, according to Curtis Brown.
The Spy Who Came In From The Cold, published in 1963, brought him worldwide acclaim and he left the service to pursue writing full time.
A statement shared on behalf of the author’s family said: “It is with great sadness that we must confirm that David Cornwell – John le Carre – passed away from pneumonia last Saturday night after a short battle with the illness.
“David is survived by his beloved wife of almost 50 years, Jane, and his sons Nicholas, Timothy, Stephen and Simon.
“We all grieve deeply his passing. Our thanks go to the wonderful NHS team at the Royal Cornwall Hospital in Truro for the care and compassion that he was shown throughout his stay. We know they share our sadness.”