Stefanos Mantzarlis was born and raised in Athens. He is a graduate of the Athens Law School and holds a Minor in Finance from Deree – The American College of Greece, as a Stavros Niarchos Foundation Scholar.

As a lawyer he is particularly active in cases of Public Law and Human Rights affairs, as well as Data Protection and more specifically in cases concerning the rights of minors, the LGBtQ+ community, nationality and immigration law and the freedom of speech. He also provides legal services to non-governmental organizations. <br> In the past he has been involved in the administration of non-governmental organizations, fundraising and the planning and execution of international events.