John Guernsey represents clients in complex commercial litigation and fiduciary litigation, with a strong focus on restrictive covenant and trade secret matters as well as trust and estate matters. John has also served as lead counsel on intellectual property litigation, products liability and complex torts, and employment litigation.
John focuses his practice in federal and state courts in Pennsylvania and New Jersey, but he has appeared in courts from the Virgin Islands to Texas in representation of clients.
Selected as a Leading Lawyer for General Commercial Litigation in Chambers USA, The Client’s Guide to America’s Leading Lawyers for Business (2010–2022)
Listed as Best Lawyers in America Philadelphia “Lawyer of the Year” for Litigation – Trusts and Estates (2017)
Named among The Best Lawyers in America® for Commercial Litigation (2010-2024), Litigation – Labor and Employment (2011-2024), Litigation – Trusts and Estates (2011-2024) by Best Lawyers
AV® Preeminent™ Peer Review Rated by Martindale-Hubbell
Listed in Pennsylvania Super Lawyers (2005–present)
American Bar Association
Montgomery County Bar Association
Philadelphia Bar Association
Fellow, American College of Trial Lawyers