Educated abroad and at the University of Oxford, le Carré taught French and Latin at Eton College from 1956 to 1958. In 1959 he became a member of the British foreign service in West Germany and continued with the agency until 1964. During this time he began writing novels, and in 1961 his first book, Call for the Dead, was published. More a detective story than a spy story, it introduced the shrewd but self-effacing intelligence agent George Smiley, who became le Carré's best-known character and was featured in several later works. Le Carré's breakthrough came with his third novel, The Spy Who Came In from the Cold (1963), which centred on Alec Leamas, an aging British intelligence agent ordered to discredit an East German official. Unlike the usual glamorous spies of fiction, Leamas is a lonely and alienated man, without a respectable career or a place in society. Immensely popular, the book was adapted into a highly successful film (1965), as were many of le Carré's later works.

After a string of moderately received novels, le Carré returned to his original protagonist with Tinker, Tailor, Soldier, Spy (1974), the first in a trilogy centred on Smiley and his nemesis, the Soviet master spy Karla. Their struggle was continued in The Honourable Schoolboy (1977) and culminated in Smiley's People (1979) with a successful attempt by Smiley to force Karla's defection to the West. In The Little Drummer Girl (1983), a young actress is persuaded by the Israeli secret service to infiltrate a Palestinian terrorist group. Le Carré's later novels include A Perfect Spy (1986), the story of a double agent; The Russia House (1989); The Secret Pilgrim (1991); The Night Manager (1993); and Our Game (1995), set after the collapse of the Soviet Union. In The Constant Gardener (2001), a British diplomat investigates his wife's death and uncovers a corrupt pharmaceutical company.