William Mackey was an American citizen and resident of Portland, Oregon, who worked for Soviet intelligence West coast operations during World War II. Mackey's main contact with Soviet inteliigence was Isaac Folkoff, the senior Communist Party West Coast liaison with the KGB.
William Mackey is referenced in the following Venona decryption:
- 117 KGB San Francisco to Moscow, 11 March 1943.
- John Earl Haynes and Harvey Klehr, Venona: Decoding Soviet Espionage in America, Yale University Press (1999).