Mariann Filó is a psychologist and LGBTQ activist based in Hungary. 

She is the member of the LGBTQ division of the Hungarian Psychological Association and an organiser of the Budapest Pride team which is an LGBTQ organisation with a feminist and anti-racist perspective. 

In Budapest Pride, she has been a member since 2016. She has always been interested in monitoring and analysing far right and religious extremism. She has been a key figure in setting up and leading the security of the Budapest Pride March and also the Festival events annually. In recent years, she has been involved in coordinating the security of several protests and other demonstrations related to human rights as well. 

In 2022, she served as the Hungarian researcher for the Global Interfaith Commission on LGBT+ lives research project on conversion therapy and since then, she has been focusing on educating the public about its harmful practices.