Jay Fox (August 20, 1870 – March 8, 1961) was an American journalist, trade unionist, and political activist. The political trajectory of his life ran through anarchism, syndicalism, and communism, and he played a significant role in each of these political movements. Fox is best remembered as a leading figure in a radical collective located in Home, Washington, near Tacoma, where he was editor of one of the leading English-language anarchist newspapers of the day, The Agitator. He became embroiled in legal difficulties related to the 1910 Los Angeles Times bombing and after 1913 made his home in Chicago, Illinois, where he was a close political associate of future Communist Party leader William Z. Foster.