The Spy Who Came in from the Cold is a 1963 Cold War spy novel by the British author John le Carré. It depicts Alec Leamas, a British agent, being sent to East Germany as a faux defector to sow disinformation about a powerful East German intelligence officer. It serves as a sequel to le Carré's previous novels Call for the Dead and A Murder of Quality, which also featured the fictitious British intelligence organization, "The Circus", and its agents George Smiley and Peter Guillam.

David John Moore Cornwell, better known by his pen name John le Carré, was a British author, best known for his espionage novels, many of which were successfully adapted for film or television. A "sophisticated, morally ambiguous writer", he is considered one of the greatest novelists of the postwar era. During the 1950s and 1960s, he worked for both the Security Service (MI5) and the Secret Intelligence Service (MI6). Near the end of his life, due to his strong disapproval of Brexit, he took out Irish citizenship, which was possible due to his having an Irish grandparent.