The Strategic Services Unit was an intelligence agency of the United States government which existed in the immediate post-World War II period. It was created from the Secret Intelligence and Counter-Espionage branches of the wartime Office of Strategic Services.
Assistant Secretary of War John J. McCloy was instrumental in preserving the two branches of the OSS as a going-concern with a view to forming a permanent peace-time intelligence agency. The unit was established on October 1, 1945 through Executive Order 9621 which simultaneously abolished the OSS.
In January 1946, a new National Intelligence Authority was established along with a small Central Intelligence Group. On April 2, the Strategic Services Unit was transferred to the new group as the Office of Special Operations and a transfer of personnel began immediately.
In 1947, the Central Intelligence Agency was established under the 1947 National Security Act, incorporating the Central Intelligence Group. In 1952, the Office of Special Operations was combined with the Office of Policy Coordination to form the Directorate of Plans, which later became the National Clandestine Service.