Prof. Konstantinos Tsimaras is the President of the Hellenic Regulatory Authority for Energy, Water and Waste (RAAEY), a position he has held since 2020, providing strategic leadership, regulatory oversight, and international representation for the Authority. In this role, he represents Greece in major European and international regulatory fora, including ACER, CEER, MEDREG, ERRA, ECRB, EMGF, the Balkan Energy School, and RegulaE.Fr.

He also serves as Vice President of WAREG and MEDREG, contributing to coordinated regulatory approaches and policy development across Europe and the Mediterranean. His responsibilities include the supervision of EU policy monitoring, cross border regulatory cooperation, and bilateral institutional engagement in the fields of energy and water.

Prof. Tsimaras has been an academic since 2002, serving as Professor of Public Law with teaching and research activities in constitutional and administrative law, energy and environmental law, EU public economic law, and broader fields of public law. His academic work is complemented by extensive public sector advisory experience. He has served as Legal Adviser to the Minister of Interior and Public Administration (2004–2009), the Minister of Tourism (2012–2015), and the President of the Republic of Cyprus (2020–2023), providing high level expertise in constitutional, administrative, and public international law.

His governance and institutional roles include service as a Member of the Board of Directors of the Hellenic Open University (2019–2024) and long standing engagement with the Council of Europe as an Expert on decentralisation and local governance (2007–2018; 2023–present). His earlier professional experience includes legal work in public entities such as Information Society S.A. and the Hellenic Audiovisual Archives, with a focus on administrative law, public procurement, and EU law.

Prof. Tsimaras holds a PhD in Law from the University of Paris I (Panthéon Sorbonne), complemented by postdoctoral research at the Universities of Toledo and Lisbon and at the Constitutional Court of Portugal. He is the author of five books and more than thirty scholarly articles, and he has delivered over thirty presentations at international conferences. He is a native speaker of Greek and fluent in French and English, with additional proficiency in Portuguese and Italian.