William Kirby
About
William Kirby is a dedicated family law attorney and the founder of William Kirby Law, LLC, with offices in Philadelphia, PA, and Mount Laurel, NJ. He focuses his practice on divorce, custody, support, and related family law matters, guiding clients through some of life’s most difficult transitions with skill, compassion, and determination.
William’s legal career spans more than two decades and includes distinguished service as a Marine Corps officer and Judge Advocate. He has held leadership roles within the military justice system, managed high-profile litigation connected to the 9/11 trials, and oversaw appellate work before the Navy and Marine Corps’ highest courts. In private practice, he established and led a family law group at a national law firm before opening his own practice to provide more personalized representation to clients.
In addition to his courtroom advocacy, William is a respected leader in the Greater Philadelphia area legal community. He currently serves as President of the Nicholas Cipriani American Inn of Court (Philadelphia Family Law Inn), Co-Chair of the Philadelphia Bar Association’s Solo and Small Firm Management Committee, and a Master Member of the Thomas Forkin American Inn of Court (South Jersey Family Law Inn). His leadership reflects his ongoing commitment to advancing the practice of family law and supporting the professional development of fellow attorneys.
William earned his law degree from Duke University School of Law and his bachelor’s degree in economics from the U.S. Naval Academy, where he was recognized as the Marine Corps Honor Graduate. He is licensed to practice in Pennsylvania, New Jersey, Washington, D.C., Maryland, and several federal courts.
Outside of his legal work, William serves as a Community Ambassador for the Philadelphia School District’s Prekindergarten Head Start Policy Council. He is also a lifelong martial artist (black belt), a certified yoga instructor, and a proud advocate for balancing discipline with compassion—values that shape both his personal life and his approach to practicing law.