Katherine Peiffer

Washington, DC

I represent States in disputes before international tribunals and courts.

As a member of Foley Hoag’s International Litigation & Arbitration Department, Kate Peiffer focuses her practice on advising and representing sovereign states and state-owned entities.

Kate obtained her J.D from Harvard Law School, where she was a member of the Civil Rights-Civil Liberties Law Review and Journal for Law and Gender, a research assistant for Prof. Ronald Sullivan, and board member of the Harvard International Arbitration Law Students Association and National Security Law Students Association.

During her 1L and 2L summers, Kate was a summer associate at the World Food Programme in Rome and a large law firm in New York and Paris, respectively. Prior to law school, Kate spent a number of years in Germany working in the non-profit sector.


  • Harvard Law School, J.D., 2020
  • University of British Columbia, B.A., 2015

Bar and Court Admissions

  • District of Columbia
  • New York


  • German
  • French



  • Counsel to a State in a confidential renewable energy arbitration. 
  • Counsel to Mauritius in an arbitration under the UNCITRAL rules concerning the termination of a land development agreement.
  • Counsel to Croatia in an arbitration proceeding under the UNCITRAL rules brought by an Austrian bank and its Croatian subsidiary under the Croatia-Austria bilateral investment treaty.
  • Counsel to Croatia in an ICSID arbitration brought under the Croatia-Netherlands bilateral investment treaty relating to investments in a retail conglomerate in Croatia.
  • Counsel to India in a confidential UNCITRAL arbitration arising from actions related to the telecommunications industry. 


  • Counsel to the Gambia before the ICJ in Application of the Convention on the Prevention and Punishment of the Crime of Genocide (The Gambia v. Myanmar).


  • Counsel to an Afghan family immigrating to the United States.
  • Advising an international human rights organization on litigation strategies.

Honors & Involvement

  • Harvard Law School Ames Moot Court, Winning Team
  • Chayes International Public Service Fellow, 2018
  • American Society of International Law
  • ICC Young Arbitrator’s Forum