[1][2] Mazey was raised in Oxford, England, and earned her BA (Hons) in Social Sciences from Leicester University in 1979.

At University of Oxford in 1985, she was granted her PhD with her dissertation titled 'The theory and practice of the 1972 French regional reform 1972–1980, with special reference to Brittany: an example of incremental decision making', under her supervisor, Vincent Wright.

[3] Mazey held senior academic and management positions at Brunel, Cambridge and Oxford Universities.

[1][2] Her first job there was as Lecturer, but she progressed through the university ranks to Academic Manager and Dean before she was named Pro-Vice-Chancellor.

[2] Mazey work includes a publication on New Zealand's public policy: Sonia Mazey and Jeremy Richardson (eds), Policy-making under Pressure: Rethinking the Policy process in Aotearoa New Zealand (Canterbury University Press, 2021).