Hester May Murray Leggatt (1905 – 26 July 1995) was a British MI5 employee. She contributed to the Second World War deception mission Operation Mincemeat. 
Life and career.
Leggatt was born in British India in 1905. Her brother, Bill Leggatt, was a lieutenant colonel in the British Army, serving in the Royal Artillery during the Second World War. Before the First World War, her family returned to the United Kingdom, where she attended Tormead School and Wycombe Abbey. She completed secretarial training at St James' Secretarial College in London. In the early 1930s, Leggatt worked as a secretary for Osbert Sitwell and for the Golden Cockerel Press.
During the Second World War, she worked as an administrative assistant for the B1a section of MI5, which was responsible for managing Double Cross agents. According to an account by Jean Leslie, a younger secretary in the section, Leggatt headed the secretarial unit with the utmost seriousness, demanding "absolute obedience and perfect efficiency" from the other administrative assistants.
As the most senior woman in the department, Leggatt was tasked with writing false love letters for the British deception mission Operation Mincemeat. The letters, alongside fake intelligence documents, were to be planted on a corpse dressed as a Royal Marine major in a ruse to trick Hitler into moving troops out of Sicily. Although Leggatt was unmarried, and would remain so for the rest of her life, the letters she wrote in the guise of a fictional fiancée named Pam were described as "chattering pastiches of a young woman madly in love, and with little time for grammar".
The love letters acted as corroborative details that helped sell the fiction that the corpse was a real British soldier. The official report on Operation Mincemeat described Leggatt's letters as achieving "the thrill and pathos of a war engagement with great success". After the war, Leggatt worked for the British Council. Leggatt never married. After retiring, she moved to Chilton, Buckinghamshire, where she died aged 89 in a nursing home on 26 July 1995.
In popular culture.
Leggatt was first portrayed by Jak Malone in the stage musical "Operation Mincemeat", which premiered in 2019 and is currently running both in the West End and on Broadway . Some lyrics in the musical's song "Dear Bill" were intentionally lifted directly from Leggatt's letters. Penelope Wilton played the role of Leggatt in the 2021 film "Operation Mincemeat".
Historical research.
Leggatt's possible contributions to the operation were first brought to mainstream attention by Ben Macintyre's 2010 book "Operation Mincemeat", though the book misspelled her name as "Leggett". 
A group of fans of the stage musical were inspired to research into the real life of Leggett, portrayed as a character in the play, as little was known about her. They contacted MI5 and were able to find out some key information about her, including the correct spelling of her surname, and that she worked for Osbert Sitwell in the 1930s, for MI5 during the Second World War, and later for the British Council. In December 2023, a plaque was installed at the Fortune Theatre in commemoration of Leggatt and her service to her country.
A book about the discovery of Leggatt's contributions to the war effort was published in June 2025. It was written by theatre archivist Erin Edwards and is titled "Finding Hester: The Incredible Story of the Hidden Woman Whose Love Letters Changed World War II in Operation Mincemeat".