Cedric Henning Belfrage (born November 8, 1904 - died June 21, 1990) was a socialist, author, propagandist, translator co-founder of the radical US-weekly newspaper the National Guardian and Soviet spy. Born in London, in 1927, Belfrage went to Hollywood. Belfrage joined the US Communist Party in 1937, but withdrew his membership a few months later. During World War II he worked in the British Security Coordination (BCS) for the Western hemisphere. In 1948, he wrote for and helped co-found---along with James Aronson and John McManus---the National Guardian (renamed the Guardian in 1967) to which he would remain affiliated until the late 1960s.
In 1943, Belfrage reported to Soviet intelligence on private discussions between Winston Churchill, and William Stephenson, the senior representative of British intelligence for the entire western hemisphere during World War II.
Jacob Golos and Elizabeth Bentley judged that he turned over "extremely valuable information from the BSC files," including volumes of instructions from MI-6 to British agents.  Belfrage reported to Soviet intelligence on private discussions between Winston Churchill, and William Stephenson, the senior representative of British intelligence for the entire western hemisphere during World War II. Belfage informed the Soviets of Allied plans and problems in Yugoslavia with Mikhailovich and Tito, as well as Churchill's discussions with Stephenson about demands for a second front in Europe. After World War II Belfrage worked for a leftist periodical The National Standard. 
According to FBI files, Belfrage was questioned by the FBI in 1947 about his involvement with the Communist Party. The interview covered his relations with Earl Browder, Jacob Golos, V. J. Jerome, and surveillances and documents about Scotland Yard and the Vichy Government of France. He was deported in 1955 as an undesirable alien.
In 1995, the decrypted VENONA intercepts--a project between the U.S. and British intelligence services to decipher Soviet wires--were made public. Un-named codename number 9 (UNC/9) is identified by US intelligence to be Belfrage. Venona also had a cover name “Charlie” that was not identified by the FBI but the 1948 Gorsky Memo in Soviet Archives corroborated Belfrage 's covert relationship with Soviet intelligence as a member of the “Sound” and “Myrna” groups. Seven Venona decrypts reference UNC/9 was involved in passing conversations between Belfrage's bureau chief and Winston Churchill on to the Soviets. Belfrage is referenced in the following Venona decrypts,
- 592 KGB New York to Moscow, 29 April 1943;
- 725 KGB New York to Moscow, 19 May 1943, p. 1
- 725 KGB New York to Moscow, 19 May 1943, p. 2
- 810 KGB New York to Moscow, 29 May 1943, p. 1
- 810 KGB New York to Moscow, 29 May 1943, p. 2
- 952 KGB New York to Moscow, 21 June 1943, p.1
- 952 KGB New York to Moscow, 21 June 1943, p.2
- 974 KGB New York to Moscow, 22 June 1943, p. 1
- 974 KGB New York to Moscow, 22 June 1943, p. 2
- 1430 KGB New York to Moscow, 2 September 1943
- 1452 KGB New York to Moscow, 8 September 1943, p. 1
- 1452 KGB New York to Moscow, 8 September 1943, p. 2
- Elizabeth Bentley, Out of Bondage, New York: Ballantine Books, 1988, p. 139.
- William L. O'Neill, A Better World: The Great Schism: Stalinism and the American Intellectuals, New York: Simon & Schuster, 1982, p. 206.
- Cedric Belfrage interview, 8 June 1947, FBI Silvermaster file, serial 2522, pgs. 47-49 (pgs. 446, 447, 448 in original).
- Cedric Belfrage statement, 3 June 1947, FBI Silvermaster file, serial 2583, pgs. 50-56 (pgs. 318 - 324 in original).
- Elizabeth Bentley deposition, 30 November 1945, FBI file 65-14603.
- John Earl Haynes and Harvey Klehr, Venona: Decoding Soviet Espionage in America, Yale University Press, 1999.