Mariana Liz has a degree in Media Studies with Film from FCSH - NOVA. In 2012, she completed a PhD in Film Studies at King's College London.

Her doctoral research, on the idea of Europe in contemporary European cinema, was funded by FCT (Portuguese council for research funding). She is the author of Euro-Visions: Europe in Contemporary Cinema (Bloomsbury, 2016), editor of Women's Cinema in Contemporary Portugal (with Hilary Owen; Bloomsbury, 2020), Portugal's Global Cinema (I.B. Tauris, 2018) and The Europeanness of European Cinema (with Mary Harrod and Alissa Timoshkina; I.B. Tauris, 2015). She has published on contemporary European cinema and Portuguese film in Aniki, New Cinemas, Northern Lights, Studies in European Cinema and the Journal of Romance Studies, among others.

She taught at King's (2009-2013) and Queen Mary (2012-2013), University of London, and at the University of Leeds (2013-2016) in the UK. Since 2017 she has been a research fellow at the Institute of Social Sciences, University of Lisbon (ICS-ULisboa), in Portugal. With Hilary Owen, she coordinated the research project Portuguese Women Directors, funded by the Calouste Gulbenkian Foundation (2017-2019).

She was on the board of AIM - the Portuguese Association of Moving Image Researchers, and is vice-chair of the Film Studies section of ECREA - the European Communication Research and Education Association.