Count Armand Alexandre de Blanquet du Chayla (25 March 1885 – 1945) was a French nobleman who converted to Russian Orthodoxy. He is chiefly remembered for giving crucial evidence and/or testimony for the prosecution at the Berne Trial in 1935 against the notorious Protocols of Zion.

Du Chayla had been a journalist at the time of the 1913 blood-libel trial of Mendel Beilis and had written in support of the accusation.^[1] At Berne he insisted on payment of 4,000 Swiss francs for his testimony, which the plaintiffs found difficulty raising.^[1] Michael Hagemeister wrote that du Chayla's testimony was full of factual errors and inconsistencies, but unfortunately still taints the historiography of the Protocols.^[1]