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Mevelyn S. Ong


Mevelyn S. Ong

New York +1-212-558-4000+1-212-558-4000 +1-212-558-3588+1-212-558-3588
[email protected]
Mevelyn Ong is an associate in Sullivan & Cromwell’s Litigation Group. Her practice focuses on international dispute resolution, specifically international arbitration and cross-border anti-corruption investigations. Ms. Ong has represented clients around the world from diverse industry sectors in international arbitrations administered under the major arbitral rules (including the ICC, LCIA, UNCITRAL and AAA Rules), as well as conducted on an ad hoc basis. She is also experienced in advising on the drafting of dispute resolution clauses in complex multi-party and multi-contract situations. She has additionally represented large financial institutions in multi-jurisdictional sanctions and anti-money laundering investigations. Prior to joining the firm, Ms. Ong practiced in Australia and East Asia, including as Deputy Counsel to the Secretariat of the ICC International Court of Arbitration.

Ms. Ong’s pro bono activity is similarly international in scope, and includes assisting individuals in their petitions for asylum and family reunification in the United States. She also sits on a number of international law and arbitration committees and boards, including NYIAC’s Program Committee, the New York City Bar’s Business & Human Rights Working Group and the International Law Committee.


  • A North American mining company in an UNCITRAL/PCA investment arbitration arising from the seizure of a mine by a Central Asian state and its state-owned entity, and other actions taken contrary to multiple international investment agreements 
  • A major European telecommunications company in LCIA arbitrations and mediation against Middle Eastern and Central Asian telecommunication companies concerning post-merger disputes arising from a share sale transaction
  • A multi-national electronics manufacturing company in AAA and UNCITRAL arbitrations concerning intellectual property contractual license disputes
  • A multi-national company regarding the arbitrability of a dispute related to liability for EC fines to be administered under the ICC Rules, in defence of and as opposed to concurrent litigation in Asia
  • A global bank in an ongoing regulatory investigation by the DOJ concerning compliance with U.S. anti-money laundering, sanctions and other applicable laws in the Middle East
  • A global bank in an investigation by OFAC concerning compliance with U.S. sanctions law in Asia