John Michael "Jack" Mullens (18 July 1896 – 5 September 1978) was an Australian politician. Born in Ballarat, Victoria, he was educated there at St Patrick's College before becoming a teacher in state schools. Having been active in the local politics of inner western Melbourne as a member of Footscray City Council, in 1937 he was elected to the Victorian Legislative Assembly as the Labor member for Footscray. He remained in the Assembly until 1945. In 1949, he was elected to the Australian House of Representatives for the new seat of Gellibrand, again as a Labor member. In 1955, together with six colleagues, he was expelled from the Labor Party and formed the Australian Labor Party (Anti-Communist). He contested Melbourne in 1955. Although he and all six of his colleagues were defeated in the elections of that year, the party itself became the Democratic Labor Party, which was instrumental in keeping Labor out of power in Canberra for twenty years. Mullens died in 1978.