Stelios H. Gregoriou is the founder and Managing Partner of Gregoriou Law Firm, a full-service Athens-based practice he established in 1992. A member of the Athens Bar Association since 1986 and admitted before the Supreme Court of Greece, he brings over three decades of experience advising and representing clients in high-stakes litigation, complex commercial matters, regulatory disputes, and cross-border transactions.

He holds an LL.M. in International Business Law from the London School of Economics and Political Science, following undergraduate studies in Law, Economics, and Political Science at the National and Kapodistrian University of Athens. This academic foundation, spanning legal, economic, and institutional frameworks, has shaped his multidimensional approach to legal strategy.

Mr. Gregoriou has been lead counsel in several landmark cases before the Greek Supreme Court, often on behalf of private and institutional investors. He is widely recognised for his success in obtaining urgent injunctive measures, enforcing domestic and foreign judgments, and securing recognition of arbitral awards. He also has extensive experience in handling civil liability, investment-related disputes, and cross-border enforcement proceedings.

Among his most complex matters, Mr. Gregoriou acted as lead counsel in a high-profile international aviation case involving multiple fatalities. He represented numerous families across parallel legal proceedings in Greece and the United States, achieving a successful resolution through cross-border mediation involving multiple defendants and jurisdictions.

In addition to his litigation practice, Mr. Gregoriou is an accomplished arbitrator and mediator. He is a Fellow of the Chartered Institute of Arbitrators (FCIArb), an Accredited Mediator certified by the Greek Ministry of Justice, a WIPO Neutral, and a Recommended Arbitrator of the Vienna International Arbitral Centre (VIAC). He has participated in numerous institutional and ad hoc arbitrations, both as counsel and co-arbitrator, and continues to promote the use of alternative dispute resolution mechanisms as efficient, enforceable, and commercially rational solutions.

His legal expertise has also led to appointments as legal adviser to successive Greek Ministers of Education and Labour, with active roles in legislative committees on labour-market reform and environmental law harmonisation with EU directives. He has held public positions including Board Member of the National Insurance Company (Ethniki Asfalistiki) and President of the EEC Youth Committee.

Mr. Gregoriou is a published legal scholar with contributions to journals such as Nomiko Vima, EEC Review, and the Greek Bank Review, writing on EU competition law, franchising, banking, biotechnology, and transnational legal structures. He is the author of The Rights of Working Youth, and served as editor and translator of Michel Rocard’s The Rules of the Game, published with a foreword by Prime Minister Konstantinos Simitis. He has also contributed to collective academic works such as the EUROGUIDE series and INE-GSEE’s research on unemployment and wage structure in the Greek economy.

He has participated in international leadership programs, including Personnalités d’Avenir (French Ministry of Foreign Affairs) and the International Visitor Program (U.S. State Department).

Mr. Gregoriou is fluent in Greek, English, and French, and represents clients across Europe, the United States, and the Middle East.

His main areas of focus include litigation, arbitration, mediation, commercial and corporate law, EU competition law, aviation law, yacht law, intellectual property, investment law, white-collar crime, and international family and inheritance law.