John S. Kiernan

Retired partner of Debevoise & Plimpton LLP

John S. Kiernan is a retired partner of Debevoise & Plimpton LLP, where he served as Co-Chair of the Litigation Department and Chair of the firm’s Ethics Committee. Now practicing as a mediator and arbitrator both independently and with Phillips ADR Enterprises, John brings decades of experience resolving complex commercial disputes. His legal practice spanned a wide range of areas including corporate governance, securities, mass torts, intellectual property, and international treaty claims. 

A nationally recognized leader in the field, John has long championed access to justice and the use of alternative dispute resolution to resolve conflict fairly and efficiently. He currently serves as Co-Chair of the New York Chief Judge’s Advisory Committee on Alternative Methods of Dispute Resolution and sits on the New York State Permanent Commission on Access to Justice. His leadership has extended to many justice-related nonprofits, including service as Board Chair of the International Institute for Conflict Prevention and Resolution (CPR), Legal Services-NYC, the Lawyers’ Committee for Civil Rights Under Law, and the Justice Resource Center. 

In addition to his extensive contributions to the legal field, John has supported numerous community and education initiatives through volunteer leadership, mentorship, and service. He is the current Board Chair of Prisoners’ Legal Services of New York and the William Nelson Cromwell Foundation, and Co-Chair of the Inner-City Scholarship Fund, Lawyers Division. John is also a former President of the New York City Bar Association and has taught as an adjunct professor at NYU Law School. He holds a B.A. and J.D., both magna cum laude, from Harvard University and Harvard Law School.