Photo of John Kiernan

John Kiernan

Of Counsel

Debevoise & Plimpton LLP

Professional Bio

John S. Kiernan transitioned from partner to counsel at Debevoise & Plimpton LLP on December 31, 2021, after more than 40 years at the firm. He currently serves as a mediator and arbitrator, independently and as a member of the panel of neutrals at Phillips ADR Enterprises (PADRE).

During John’s time at Debevoise, he served on the firm’s Management Committee, co-chaired its Litigation Department for twelve years, and chaired its Ethics Committee for twenty-seven years. His client representations embraced a broad range of commercial litigations, arbitrations, mediations and internal investigations, including disputes relating to contracts, purchases and sales of businesses, corporate governance, derivative and class action claims, international treaties, securities claims, patents and other intellectual property, consumer fraud, accountant liability and mass torts.

John is the Board Chair of Prisoners’ Legal Services of New York and Co-Chair of the Inner City Scholarship Fund, Lawyers Division. He has previously chaired the Boards of the International Institute for Conflict Prevention & Resolution (CPR), Legal Services-New York City, the Lawyers’ Committee for Civil Rights Under Law, Volunteers of Legal Service (VOLS), the Justice Resource Center and the New York City Bankruptcy Assistance Project (which he co-founded). He has additionally served as a director or trustee of the City Bar Justice Center, New York Alliance for the Public Schools, Practicing Attorneys for Law Students, United Way of Pelham, NY, the Pelham Art Center, the Federal Bar Council, the Village Board of Pelham Manor, the International Senior Lawyers Project and the Point O’Woods, NY Association. He served for 15 years as a volunteer coordinator for the AmeriCares/HomeFront home rehabilitation project, and for 28 seasons as a travel soccer coach.


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