LAWYER PROFILE
Stephen Fietta KC

Stephen Fietta KC

UK 2026

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Ranked in 2 practice areas

About

Provided by Fietta LLP

UK

Practice Areas

Stephen Fietta KC founded Fietta LLP in 2015. He is one of the world’s leading public international law practitioners. He advises State clients with respect to many of the world’s most high-stakes, high-profile and sensitive public international law issues, including territorial, sovereignty and natural resources disputes, the law of the sea and maritime boundary delimitation, international humanitarian law and the law of armed conflict, international environmental law, transboundary water law, human rights, decolonisation and rights to self-determination, treaty interpretation and international investment law.

Stephen has advised (including as lead and coordinating counsel) on cases before the International Court of Justice (ICJ) (both contentious and advisory opinion proceedings), International Tribunal for the Law of the Sea (ITLOS), European Court of Justice, European Court of Human Rights, Inter-American Court of Human Rights and multiple domestic courts. He has acted in State-to-State arbitration proceedings, including under the UN Convention on the Law of the Sea (UNCLOS) and the Indus Waters Treaty. He has acted in more than 50 investment arbitration cases under the World Bank (ICSID), UNCITRAL, SCC and other rules, a number of which have featured ground-breaking awards on jurisdiction, merits and/or damages.

Stephen was appointed Queen’s Counsel in January 2019. Before establishing Fietta in 2015, Stephen co-founded the world’s first specialist public international law firm (Volterra Fietta) in 2011. Prior to that, he was a partner specialising in public international law at a leading US and global law firm. Both of those practices were consistently top-ranked at the time. Stephen regularly manages large teams of lawyers (including specialist or domestic co-counsel), experts and witnesses across multiple jurisdictions.

Stephen teaches the Geopolitics, Resources and Territory MA course at King’s College, London.

Chambers Review

Provided by Chambers

Chambers Guide to the Legal Profession

Public International Law - UK-wide

Star Individual
Star Individuals

Individual Editorial

Stephen Fietta KC enjoys a sterling reputation for his expertise in PIL. He is regularly instructed on complex mandates concerning issues such as boundary delimitation and state sovereignty, and is praised for his specialist knowledge of the Law of the Sea. He also has a strong investor-state practice, handling a range of BIT claims.

International Arbitration - UK-wide

Band 1
Band 1

Individual Editorial
Stephen Fietta KC is a recognised authority in investment treaty arbitration and broader PIL concerns. He acts for an extensive roster of clients, including major corporations and individuals, in BIT claims and other disputes involving sovereign states.

Strengths

Provided by Chambers

  • His in-depth understanding of complex legal issues, combined with his strategic approach, allows him to deliver outstanding legal advice.

    Public International LawChambers Guide to the Legal Profession
  • Stephen Fietta is one of the best and knows how to get people working together perfectly.

    Public International LawChambers Guide to the Legal Profession
  • He has a very commercial approach with clients.

    International ArbitrationChambers Guide to the Legal Profession
  • Stephen is a highly effective advocate at trial.

    International ArbitrationChambers Guide to the Legal Profession
  • Stephen is a fantastic lawyer and a very nice person!

    International ArbitrationChambers Guide to the Legal Profession
  • Stephen is a consummate lawyer and professional, and is always a pleasure to work with

    International ArbitrationChambers Guide to the Legal Profession

Ranked Individuals at Fietta LLP (4)

UK-wide

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