Karla is a recurring character in the works of John le Carré. A Soviet Intelligence officer, he is the head of the Thirteenth Directorate of Moscow Centre, le Carré's fictional version of the KGB, and the nemesis of le Carré's frequent protagonist George Smiley. Karla is nominally an unseen character who operates either through functionaries, hitmen, or by turning his enemies into double agents. Although other characters recount their past meetings with him, he only appears once during the events of the books. His real name is never revealed; instead, he takes his code name from that of the first spy network that he recruited.
Karla is the central antagonist in Tinker Tailor Soldier Spy, The Honourable Schoolboy, and Smiley's People, three novels which were later published as a single omnibus edition entitled Smiley Versus Karla or The Quest for Karla in the US. He is also the title charcter in the first George Smiley continuation novel, Karla's Choice by Nick Harkaway, which is set in the period some time before Tinker Tailor Soldier Spy.
In the BBC's television adaptations of both Tinker Tailor Soldier Spy and Smiley's People, Karla is played by British actor Patrick Stewart. Karla is only seen briefly in one scene in each production and does not speak.