Philip Jacob Jaffe (March 20, 1895 – December 10, 1980) was a left-wing American businessman, editor and author. He was born in Ukraine and moved to New York City as a child. He became the owner of a profitable greeting card company. In the 1930s Jaffe became interested in Communism and edited two journals associated with the Communist Party USA. He is known for the 1945 Amerasia affair, in which the FBI found classified documents in the offices of his Amerasia magazine that had been given to him by State Department employee John S. Service. He received a minimal sentence due to OSS/FBI bungling of the investigation, but there were continued reviews of the affair by Congress into the 1950s. He later wrote about the rise and decline of the Communist Party in the USA.