Naomi Briercliffe is a partner in the International Dispute Resolution Practice Group based in London. She has extensive experience representing clients as counsel and advocate in international commercial and investor-state arbitrations under the rules of major arbitral institutions, as well as in ad hoc proceedings. She has also acted in state-to-state disputes, including before the International Court of Justice and Iran-US Claims Tribunal, and advises on other matters of public international law.

Naomi acts for global clients, particularly in Europe, the Middle East and Africa, and brings specialised expertise in the energy, aerospace, private equity, technology and infrastructure sectors.

She is recommended by Chambers UK and The Legal 500 UK for both international arbitration and public international law. The directories have described her as “incredibly impressive”, “very smart and hard-working” and “detail-oriented”. In 2021, she was also ranked among the top 10 most-highly-regarded “future leader” arbitration practitioners in EMEA by Who’s Who Arbitration, and – since 2022 – has been ranked as a Who’s Who Arbitration market leader. She is also included in The Legal 500 London Arbitration Powerlist.

Naomi is a qualified Solicitor Advocate and a Registered Foreign Attorney in the State of New York. She speaks English and French.


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Investment Treaty

  • Counsel to the UAE in two separate investment treaty arbitrations under the ICSID Rules arising out of construction projects.
  • Counsel to European investors in multiple ICSID arbitrations against the Kingdom of Spain under the Energy Charter Treaty arising out of renewable energy investments.
  • Counsel to a European investor in ICSID annulment proceedings and US enforcement proceedings against the Kingdom of Spain.
  • Counsel to the Kingdom of Saudi Arabia in an investment treaty arbitration against a Turkish contractor arising out of a construction project.
  • Counsel to a British oil and gas company in ICSID, UNCITRAL and SCC proceedings against Ukraine under the UK-Ukraine bilateral investment treaty (BIT), the Netherlands-Ukraine BIT and the Energy Charter Treaty (including successful applications for emergency and interim measures).
  • Counsel to the Islamic Republic of Iran in an UNCITRAL arbitration against a Turkish telecommunications operator under the Iran-Turkey BIT.
  • Advising various private equity and litigation fund investors on the potential purchase of awards and claims (including full merits assessments and advice on enforcement).


  • Counsel to an Israeli individual in an ad hoc arbitration arising out of a shareholders agreement (English law).
  • Counsel to a group of companies and Israeli individuals in London-seated consolidated arbitration proceedings under the LCIA Rules relating to the break-up of a business partnership involved in turn-key projects in Africa (English law).
  • Advising an aerospace major in relation to a dispute with a private jet operator arising under an outfitting agreement (English law).
  • Counsel to a heavy industries manufacturer in relation to the challenge of an ICC award under s 67 of the English Arbitration Act 1996.
  • Advising an American multinational technology company on its international dispute strategy in relation to competition proceedings.
  • Counsel to European energy company in a London-seated ICC arbitration arising out of a nuclear fuel supply contract (English law).
  • Advising a Middle Eastern gas company in a dispute under a royalty agreement.
  • Counsel to a mining company in London-seated LCIA proceedings under a loan agreement (English law).
  • Counsel to a European aerospace manufacturer in an AAA arbitration (New York seat) concerning warranty claims (New York law).
  • Advising an international oil company in relation to a post-merger and acquisition (MA) dispute concerning a power station in Denmark.
  • Advising a consortium of international oil companies in relation to a dispute under a farm-in agreement.
  • Counsel to a hospitality company in proceedings for the enforcement of an ICC arbitration award against a Tanzanian hotel management company (proceedings in England and Tanzania).
  • Counsel to the South African arm of a software company in an LCIA arbitration against a Nigerian bank under a licence and implementation agreement (English law).
  • Counsel to a consortium of East Asian national oil companies in a dispute with a North African state under a pipeline agreement.
  • Counsel to a South African electricity company in an ICC arbitration with a consortium of West African energy management company (Malian law, Malian seat).

Public International Law

  • Counsel to the Islamic Republic of Iran in three cases (A15, B16 and B1) against the United States before the Iran-US Claims Tribunal.
  • Counsel to Cambodia in Request for Interpretation of the Judgment of 15 June 1962 in the Case concerning the Temple of Preah Vihear (Cambodia v Thailand) before the International Court of Justice.
  • Advising sovereigns, international organisations and companies on matters of public international law, including law of the sea, international humanitarian law, the law of treaties, space law, and immunities.


  • College of Law, London, LL.B., first class honours
  • College of Law, London, Legal Practice Course, distinction
  • University of Cambridge, King's College, M.A. (Cantab)
  • University of Cambridge, King's College, BA (Hons)


  • England and Wales, 2011
  • High Rights of Audience, 2015
  • Registered Foreign Attorney, New York, 2018


  • English
  • French
  • Chambers UK – “Up and Coming” Public International Law, 2018–2023 and Commercial Arbitration, 2019–2023.
  • The Legal 500 UK – “Rising Star,” Public International Law, 2018–2023 and Commercial Arbitration, 2019–2023.
  • Who’s Who Legal: Arbitration Leaders 2022–2023.
  • Who’s Who Legal: Arbitration Leaders 2022–2023.
  • Best Lawyers: “Ones to Watch” International Arbitration, 2023.
  • Featured in Legal Business as a “Next Generation” arbitration lawyer, 2021–2022.
  • The Legal 500 London Arbitration Powerlist 2023.


  • Author, “Legitimate Expectations”, Elgar Encyclopedia of International Economic Law (eds. Cottier and Nadakavukaren), forthcoming edition.
  • Co-author, “Dispute resolution in the European energy sector", Routledge Handbook of Energy Law (eds. Hunter, Herrera, Crossley, Alvarez), 2020.
  • Co-author, “Article 52(1)(e)”, The ICSID Convention, Regulations and Rules; A Practical Commentary (Fouret, Gerbay and Alvarez ed.), 2019.
  • Co-author, “Human-rights-based Claims by States and “New-Generation” International Investment Agreements”, Kluwer Arbitration, 2018.
  • Co-editor, “African Border Disputes: A Users Guide”, African Union, 2016.

Speaking Engagements

  • “Disputes involving States arising out of War”, London International Disputes Week, London, May 2023.
  • “Ukraine, Russia and Issues of Territory”, GAR Live BITs, London, May 2023.
  • “Energy Arbitration in Times of Crisis”, Cambridge Arbitration Day, Cambridge, April 2023.
  • “Arbitration in Times of Conflict”, Tel Aviv Arbitration Week, Tel Aviv, March 2023.
  • “Special issues relating to Intra-EU awards”, Boies Schiller Flexner and Farrer & Co Roundtable on Judgment and Enforcement Trends, London, February 2023.
  • “Contractual excuse doctrines”, ITA-IEL-ICC Joint Conference on International Energy Arbitration, Houston, January 2023.
  • “Investment arbitration and domestic criminal proceedings”, BIICL Investment Treaty Forum, London, October 2022.
  • “Young Practitioners and our Future”, ICCA Congress, Edinburgh, September 2022.
  • “Specialised Dispute Resolution for Commercial Space Disputes – A Practitioners Perspective”, International Astronautical Space Congress, Paris, September 2022.
  • “After Achmea, PL Holdings and Komstroy, the EU is still an attractive destination for investment” (Oxford-style debate for the Young EFILA launch), Young EFILA, Amsterdam, June 2022.
  • “Arbitration and FDI”, SKOCH India Forum and LITFest, April 2022.
  • Who’s Who Legal Future Leaders: Arbitration Conference, London, April 2022.
  • “Regionalism v Globalisation”, Tel Aviv Arbitration Day, Tel Aviv, March 2022.
  • “Can an investor waive its right to investment treaty arbitration?”, virtual event, Milan Arbitration Week, February 2022.
  • “Legitimate Expectations”, virtual event, American Society of International Law (ASIL), January 2022.
  • “Difficult Discussions: Mastering Tricky Conversations in your Arbitration Career”, virtual event, London VYAP, January 2022.
  • Co-presenter, “An overview of ICSID and UNCITRAL reform initiatives” (co-presented with ICSID), Africa Arbitration Academy, Africa and ISDS, October 2021.
  • “Stronger Together: A Look Back at Remote Community Building and Ahead to the Future for International Arbitration”, virtual event, Arbitral Women (LIDW), May 2021.
  • “Investor obligations in investment treaty arbitration”, virtual event, Mute Off Thursdays, March 2021.
  • “Failure to perform due to pandemics and arbitration”, virtual event, V Oxford Arbitration Day, November 2020.
  • “CEA-40, The enforcement of intra-EU awards: Will the US come to the rescue?”, virtual event, November 2020.
  • “RPC, 20 Essex and CIArb, Being indispensable in (virtual) Arbitration: How junior members of the team can impress”, virtual event, October 2020.
  • GAR Live Women, London, December 2019.
  • CIArb YMG Annual Conference, Edinburgh, November 2019.
  • 2nd Annual Who’s Who Legal Future Leaders: Arbitration Conference, London, June 2019.
  • “Debunking Myths in Investor-State Arbitration”, LSE, London, March 2019.
  • ·AILA arbitration training course for African arbitration practitioners, London, September 2017 and 2016.
  • “A Paradigm Shift in International Investment Law”, ·AILA, Cairo, April 2017.
  • UNCTAD and Islamic Development Bank training course for States on negotiating international investment treaties, Casablanca, January 2015, January 2016, January 2017.
  • “Developments in Investment Treaty Arbitration”, Nairobi Arbitration Centre Inaugural Conference, Nairobi, December 2016.
  • “India: Changes and Challenges”, Indian Council of Arbitration Event, Delhi, July 2016.
  • “1996 and All That: A Memorable History of the 1996 Arbitration Act”, ·Essex Court Chambers and Allen & Overy LLP, London, June 2016.
  • “Cases under the ECT against the Kingdom of Spain”, International Energy Arbitration Congress, Santa Cruz, May 2016.
  • “Arbitrating in the European Union”, Arbitral Women and Queen Mary University Event, London, April 2016.
  • “International Energy Investment and the ECT”, ICC YAF, Milan, April 2016.
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