Oonagh Sands

Senior Associate


Oonagh Sands is a dually-qualified English and US-lawyer. The Legal 500 has recognised Oonagh as a “Rising Star” in public international law.

She has significant experience representing sovereign States and their State-owned entities, as well as individuals and private entities, before leading world dispute resolution fora. She has represented clients before the International Court of Justice, the Permanent Court of Arbitration, as well as investor-State arbitral tribunals constituted under ICSID, ICSID Additional Facility, UNCITRAL, SCC and ICC rules. Oonagh has also advised sovereign States, State-owned entities, and private entities on the law of sovereign immunity and the recognition and enforcement of arbitral awards under English law.  She has counselled States on territorial and maritime boundary disputes, the law of State responsibility, treaty interpretation, international environmental law, and the law of the sea.  In addition, Oonagh has represented clients in international commercial arbitration proceedings conducted under ICC, LCIA, SCC and UNCITRAL Rules, as well as multiple domestic proceedings before English and U.S. federal courts.  In 2018, The American Society of International Law appointed Oonagh to serve on the steering committee for its signature topic “Beyond National Jurisdiction: Human Activities in the Oceans, Polar Regions, Cyberspace and Outer Space”, following her tenure as elected Co-Chair of the Society’s ‘Space Law Interest Group’.

Prior to joining Fietta, Oonagh worked at major law firms in Washington DC and London. Oonagh has also worked for the United Nations Office of Legal Affairs in New York, the European Commission in Brussels, and the Institute of International Economic Law at Georgetown University Law Center in Washington DC.

She speaks French and Spanish.

In 2016, Oonagh was recognised by The Irish Times for women’s influence in global public affairs.

Oonagh’s full curriculum vitae is available here.