Control is a fictional character created by John le Carré who is the head of the British overseas intelligence agency (nicknamed "The Circus" after its location in Cambridge Circus, London). He is a character in the novels The Spy Who Came in from the Cold and The Looking Glass War, and is referred to in Tinker Tailor Soldier Spy and several others, usually by le Carré's recurring protagonist George Smiley, who served as Control's right-hand man.
"Control" is a nom de guerre, based on the real codename for the head of MI6. The character's real name is never given, and it is suggested that he successfully kept his true identity secret even from his inner circle of advisors. His wife believes him to be a minor civil servant in the Ministry of Agriculture and Fisheries. In the original screenplay for the film adaptation of Tinker Tailor Soldier Spy, Smiley muses that Control had once told him that Howard Staunton was the greatest chess master Britain had ever produced. "Staunton" later turns out to be the name that Control used for the rental of a flat he uses.