Floyd Cleveland Miller (March 20, 1912 – June 4, 1988)[1] was a member of the Communist Party USA (CPUSA), who confessed in 1954 to having worked for the Soviet intelligence agencies.
Later, he was to infiltrate the Socialist Workers Party (SWP) and become an activist, while sending reports to the CPUSA and Soviet intelligence.
In the first half of 1944, Miller met in New York with Jack Soble who provided the KGB with microfilm of the page proofs of Leon Trotsky's biography of Joseph Stalin.
Miller confessed his covert activities to the FBI in 1954 and appeared as a witness in Robert Soblen's espionage trial in 1961.
He testified that his 1944 Mexican assignment included investigating reports of a budding alliance between Trotskyists, anarchists, and other radical groups in contact with French writer Victor Serge, who was living in exile.