Detective Inspector Walter Henry Thompson BEM (3 December 1890 – 18 January 1978) was a British police officer who is best known as the bodyguard of Winston Churchill for eighteen years, between 1921 and 1935, and between 1939 and 1945 during World War II. Thompson reportedly saved Churchill's life on numerous occasions. When he finally retired after the war, he published a memoir that made him famous in the United Kingdom and the Western world.