Alec Guinness was asked to play George Smiley for a third time but he passed. Anthony Hopkins, who had previously starred in John le Carré's The Looking Glass War (1970), was offered the role and read a script, but withdrew from the project when script changes were made that he didn't like. Denholm Elliott was approached with just three days until production was to start. Elliott turned it down initially as he was living in Spain and returning to the UK would mean he would be landed with a bigger tax bill. He then agreed to play the role when he was offered twice the fee.
Writer John le Carré partially based his famous George Smiley character on a friend, the Lincoln College tutor and Oxford University don, the Reverend Vivian Green. Smiley was also based on le Carré's boss at Mi5, Lord Clanmorris, who wrote crime novels under the pseudonym of John Bingham.
This filmed adaptation of a John le Carré novel is his only ever book which is not set inside the world of spies and espionage.
Rupert Davies was the first actor to play'John le Carré''s famous George Smiley in The Spy Who Came in from the Cold (1965); James Mason was the second actor to play George Smiley character on screen and TV in The Deadly Affair (1967) though the character was renamed Charles Dobbs; Sir Alec Guinness was the third, he played him twice, in Tinker Tailor Soldier Spy (1979) and Smiley's People (1982); Denholm Elliott was the fourth actor to play Smiley in A Murder of Quality (1991); whilst Gary Oldman was the fifth actor to play George Smiley in Tinker Tailor Soldier Spy (2011).