Finn Mackay (born 1977/1978) is a British sociologist and radical trans feminist campaigner. Mackay is a lecturer in sociology at the University of Bristol and identifies as "a queer butch, or transmasc, identifying with much in the trans-with-an-asterisk label". During their teenage years, Mackay was part of an all-women's peace camp, where they became involved in lesbian feminism. In 2021, Mackay wrote Female Masculinities and the Gender Wars: The Politics of Sex.