Civil Air Transport (CAT) was a Nationalist Chinese airline, later owned by the U.S. Central Intelligence Agency (CIA), that supported the United States' covert operations throughout East and Southeast Asia. During the Cold War, missions consisted in assistance to "Free World" allies according to the Mutual Defense Assistance Act of 1949. The CIA-owned airline Air America, which primarily operated in Southeast Asia (particularly in Laos and Vietnam), was a spin-off of CAT, as was the CIA's Taiwan-based aviation maintenance facility, Air Asia.

CAT was created by Claire Chennault and Whiting Willauer in 1946 as Chinese National Relief and Rehabilitation Administration (CNRRA) Air Transport. Using surplus World War II aircraft such as the C-47 Dakota and the C-46 Commando, CAT airlifted supplies and food into war-ravaged China. It was soon pressed into service to support Chiang Kai-shek and his Kuomintang forces in the civil war between them and the communists under Mao Zedong. Many of its first pilots were veterans of Chennault's World War II combat groups, popularly known as Flying Tigers. (Other of Chennault's veterans went on to form another air transport company, the Flying Tiger Line. This was a completely separate operation from Civil Air Transport and the follow-on Air America.)

By 1950, following the defeat of Chiang's forces and their retreat to Taiwan, the airline faced financial difficulties. The CIA formed a private Delaware corporation called Airdale Corporation, which formed a subsidiary called CAT, Inc. The subsidiary corporation purchased nominal shares of Civil Air Transport. CAT maintained a civilian appearance by flying scheduled passenger flights while simultaneously using other aircraft in its fleet to fly covert missions.

With the spread of communism throughout Southeast Asia, CAT's mission changed.

During the Chinese Civil War, under contract with the Chinese Nationalist government and later the CIA, CAT flew supplies and ammunition into China to assist Kuomintang forces on the Chinese mainland, primarily using C-47 and C-46 aircraft. With the defeat of the Kuomintang in 1949, CAT helped to evacuate thousands of Chinese to Taiwan.

During the Korean War, CAT airlifted thousands of tons of war materials to supply United States military operations, including support of Kuomintang holdouts based in Burma (Operation PAPER). On 29 November 1952, a CAT C-47 left Seoul on a mission to collect an anti-Communist Chinese agent in the foothills of northeastern China, using a "pole and line" technique. The mission was apparently compromised and Chinese forces were waiting for them. Approaching low over the ground, it was attacked by small-arms fire, and crash-landed near the town of Antu in China's Jilin province. The pilots, Robert Snoddy and Norman Schwartz were killed during the crash and subsequent fire, and were buried nearby. The two CIA officers, John T. Downey and Richard G. Fecteau survived and were immediately taken prisoner by Chinese forces, who were waiting for the flight. Downey and Fecteau were held by China and regularly interrogated for nearly twenty years. Fecteau was released unexpectedly following Nixon's visit to China in 1972, but Downey was released only after Washington publicly acknowledged their spy mission in 1973.

At the time the families of the pilots were told, in order to keep the CIA's covert actions in China secret, that they had crashed into the Sea of Japan on a routine flight to Tokyo. In 2001, China allowed the US Defense Department's Prisoner of War and Missing in Action (POW/MIA) office to conduct a recovery effort for the bodies of the pilots. In 2005 the POW/MIA office announced that it had identified the remains of Robert Snoddy using DNA analysis. Schwartz's remains have not been recovered.

The 1952-1953 edition of Jane's All The World's Aircraft lists the head office address as Suite 309, Kass Building, 711 14th Street, N.W., Washington, D.C., with the footnote that the company had reregistered in the U.S. The president is given as Whiting Willauer, and the fleet listed as 23 Curtiss C-46 Commando and 4 Douglas DC-3 aircraft.