Hilaire du Berrier (1905 – October 12, 2002) was a pioneer American pilot, barnstormer, and spy.
Born as Hal du Berrier in 1905, in Flasher, North Dakota, he attended the Northwestern School of Journalism and, in Paris, the Institute of Political Science.
He worked as a commercial artist in Chicago, Illinois, in 1925 and later joined a flying circus. He then moved to France, where took the name Hilaire. In Paris, he learned in 1936 that the Ethiopian emperor, Haile Selassie, was hiring mercenary pilots to fight against the Italian occupation and so in that year, he went to Addis Ababa, the capital of Ethiopia.
From 1936 to 1937, Berrier joined the Spanish Civil War on the side of the government but was arrested as a spy for the rebels.
He worked for the Office of Strategic Services briefly, as an informant, in Shanghai after the Japanese surrender in 1945.
He worked as a journalist in Vietnam and wrote a strongly anti-communist article in the American Mercury in 1958.
He died on October 12, 2002 in Monaco.