Francis Beverley Biddle (May 9, 1886 – October 4, 1968) was an American lawyer and judge who was the United States Attorney General during World War II.

On February 9, 1939, Roosevelt nominated Biddle to the United States Court of Appeals for the Third Circuit, to a seat vacated by Joseph Buffington.

During this time he also served as chief counsel to the Special Congressional Committee to Investigate the Tennessee Valley Authority from 1938 to 1939.

In 1941, he authorized the prosecution of 29 Socialist Workers Party members in a move that was criticized by the American Civil Liberties Union.

[12] In 1942, Biddle became involved in a case in which a military tribunal appointed by Roosevelt tried eight captured Nazi agents for espionage and for planning sabotage in the United States as part of the German Operation Pastorius.

Lieutenant Colonel Kenneth Royall challenged Roosevelt's decision to prosecute the Germans in military tribunals by citing Ex parte Milligan (1866), a case in which the U.S. Supreme Court ruled that the federal government could not establish military tribunals to try civilians in areas that civilian courts were functioning, even during wartime.

Biddle responded that the Germans were not entitled to have access to civilian courts because of their status as unlawful combatants.

The US Supreme Court upheld that decision in Ex parte Quirin (1942) by ruling that the military commission that was set up to try the Germans was lawful.

[13] Biddle was one of the few top officials, along with FBI Director J. Edgar Hoover and Secretary of Interior Harold L. Ickes, who opposed the wartime internment of Japanese Americans from the start.

"[17] Biddle strengthened his department's efforts on behalf of African-American civil rights by instructing United States attorneys to direct their prosecutions against forced labor in the South away from the usual practice of charging "peonage", which required them to find an element of debt, toward bringing charges of "slavery" and "involuntary servitude" against employers and local officials.

They had two sons: Biddle died on October 4, 1968, of a heart attack at his summer home in Wellfleet, Massachusetts, on Cape Cod, at the age of 82.