Louis Francis Budenz (pronounced "byew-DENZ"; July 17, 1891 – April 27, 1972) was an American activist and writer, as well as a Soviet espionage agent and head of the Buben group of spies.
He began as a labor activist and became a member of the Communist Party USA.
In 1945 Budenz renounced Communism and became a vocal anti-Communist, appearing as an expert witness at various governmental hearings and authoring a series of books on his experiences.