Toby Esterhase

Toby Esterhase is a fictional character who appears in several of John le Carré's spy novels that feature George Smiley, including Tinker Tailor Soldier Spy, The Honourable Schoolboy, Smiley's People, and The Secret Pilgrim. Esterhase also makes a cameo appearance in Le Carré's A Legacy of Spies. Esterhase is an intelligence officer in The Circus, le Carre's fictionalized version of MI6.

He is the head of the Lamplighters, the section of The Circus responsible for surveillance and wiretapping. Hungarian by birth, Esterhase is an Anglophile with pretensions of being a British gentleman. He is the Circus' resident ne'er-do-well, often involving himself in either morally questionable or outright criminal plots, although his superiors look the other way due to his high level of competence and loyalty to the service.

Initially something of an antagonist to Smiley, due to his loyalty to Smiley's bureaucratic nemesis Percy Alleline, Esterhase ultimately switches allegiances and becomes one of Smiley's top lieutenants, aiding him in a number of high-profile intelligence missions.