Peter Taaffe (born April 1942) is a British Marxist political activist and journalist.
He is the general secretary of the Socialist Party of England and Wales and member of the International Executive Committee of the Committee for a Workers' International (CWI), which has sections in over 45 countries around the world.Taaffe was the founding editor of the Trotskyist Militant newspaper in 1964, and became known as a leading member of the entryist Militant group.
Taaffe was expelled from the Labour Party in 1983, along with four other members of Militant's editorial board
Taaffe was influential in the policy decisions of Liverpool City Council of 1983–1987, according to the council's deputy leader Derek Hatton, in the formation of the Militant tendency's policy regarding the Poll Tax in 1988–1991, and the Militant tendency's "open turn" from the Labour Party in the late 1980s, becoming general secretary of Militant's eventual successor, the Socialist Party in 1997.