Tasos Chatzivasileiou was born in Serres, in 1981. He has been an elected Member of Parliament for Serres with Nea Demokratia party, since 2019.

He is an Assistant Professor of International Relations and the EU at the Hellenic American University (New Hampshire, USA). In 2020, he was awarded a PhD in Political Science and History from Panteion University of Athens. He has worked as a Special Advisor at the Greek Ministry of Foreign Affairs and the Hellenic Parliament, and as a Research Fellow at the Ministry of Foreign Affairs of Cyprus. He has participated in various research projects in Athens, Brussels, Strasbourg, Istanbul and Nicosia. In the private sector, he has worked as an International Business Development Consultant, specializing in the utilization of European programs and the implementation of business synergies in the Greek and international markets. In addition, he has participated in the writing of books related to International Relations and History. He speaks English, French, Turkish and Spanish.

As a Member of Parliament, he has served as Secretary of the parliamentary Committee on National Defense and Foreign Affairs and 1st Vice-Chairman of the parliamentary Committee on European Affairs. Moreover, he has been an active Member of the Parliamentary Assembly of the Council of Europe (PACE), where he was elected at various positions of responsibility. Also, he was rapporteur of PACE for issues related to youth. In December 2019, the Greek Prime Minister and President of Nea Demokratia Kyriakos Mitsotakis appointed him as International Secretary of the party. In January 2025, he was appointed as Deputy Minister of Foreign Affairs, responsible for Economic Diplomacy and Extroversion.