Milicent Jessie Eleanor Bagot, CBE (28 March 1907 – 26 May 2006) was a British intelligence officer. She was the purported model for the character Connie Sachs, the eccentric Sovietology expert who appeared in John le Carré's novels Tinker, Tailor, Soldier, Spy, The Honourable Schoolboy and Smiley's People, and more recently for the character of "Muriel Edge" in two of the 'Troy' novels by John Lawton – Black Out and Old Flames.
The daughter of Cecil Frederick Villiers Bagot and his wife, Ethel Garratt, Bagot was educated at Putney High School and Lady Margaret Hall, Oxford (MA), where she took a Class IV in Classical Moderations in 1927.
She entered the Ministry of Defence from Scotland Yard as a secretary in 1931 and worked for both MI5 and MI6. During her long career (she retired in 1967) Bagot became one of the security service's principal experts on Soviet Communism. She was the first person to warn MI5 that Kim Philby, MI6 officer and Soviet KGB double agent, had been a member of the Communist party. Philby's denial of this fact led to his eventual resignation from MI6, and his flight to Moscow.
Bagot also wrote a definitive account of the 1924 Zinoviev Affair in which a forged letter purported to be from Grigory Zinoviev, president of the executive committee of the Comintern, urged the British working class to rise up in an armed insurrection. The publication of the letter is thought by some to have had an effect on the subsequent electoral defeat of the Ramsay MacDonald-led Labour Government. It has also been suggested that MI5 or MI6 may have been involved in leaking the forged letter.
- Condell, Diana (16 June 2006), "Milicent Bagot: First woman appointed to a senior rank in MI5", The Guardian, retrieved 22 December 2011
- Burke's peerage & baronetage. London, UK: Fitzroy Dearborn. 1999. p. 164. ISBN 2-940085-02-1.
- Oxford University Calendar 1932, Oxford : Oxford University Press, 1932, pg. 314
- C. Andrew, The Defence of the Realm : The Authorized History of MI5, London : Penguin Books, 2009, pg.131