Jack Guernsey is an experienced litigator who has successfully represented many 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. He has also served as lead counsel on intellectual property litigation, products liability and complex torts, and employment litigation. Clients value Jack’s keen analysis and formidable advocacy skills. Jack 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.
Jack served five years on Army active duty, including one tour in Vietnam, where he was awarded a Silver Star and a Bronze Star. He served 25 years in the reserve forces, the last 21 in the Delaware Army National Guard, in positions of responsibility, including four years as a brigade commander, before retiring in 1999.
Harvard Law School, J.D.
United States Military Academy at West Point, B.S., with distinction
U.S. District Court for the Eastern District of Pennsylvania
U.S. District Court for the Middle District of Pennsylvania
U.S. District Court for the Western District of Pennsylvania
U.S. District Court for the District of New Jersey
U.S. Court of Appeals for the Third Circuit
Federal U.S. Circuit Court of Appeals
"He's able to hone in on the real issues quickly and present them effectively."
Chambers USA 2022
"John Guernsey can take a complicated, difficult situation and represent the client effectively."
Chambers USA 2022
"Jack is praised as being 'thoughtful and strategic' and a 'very good trial lawyer.'"
Chambers USA 2020
Jack’s free time is spent in travel and outdoor activities, including skiing, hiking, and fighting the waves at the Jersey Shore.
Fellow, American College of Trial Lawyers
Selected as a Leading Lawyer for General Commercial Litigation in Chambers USA, The Client’s Guide to America's Leading Lawyers for Business (2010–present) (View methodology. No aspect of this advertisement has been approved by the Supreme Court of New Jersey.)
Listed in Best Lawyers in America for Commercial Litigation; Intellectual Property; Labor & Employment; Litigation-Trusts and Estates (2010–present) (View methodology. No aspect of this advertisement has been approved by the Supreme Court of New Jersey.)
Listed as a Best Lawyers in America Philadelphia "Lawyer of the Year" for Litigation - Trusts and Estates (2017)
AV® Preeminent™ Peer Review Rated by Martindale-Hubbell
Philadelphia Bar Association
Montgomery County Bar Association
American Bar Association
Listed as a Pennsylvania Super Lawyer (2005–present) (View methodology. No aspect of this advertisement has been approved by the Supreme Court of New Jersey.)