Diana Manning is an accomplished litigator and certified Civil Trial Attorney in New Jersey with more than three decades of experience representing clients in complex commercial litigation, legal ethics, and professional liability matters. She also maintains an active appellate practice and has argued nine times before the New Jersey Supreme Court.
Diana dedicates a significant portion of her practice to advising attorneys and law firms on ethics and compliance issues, including conflicts of interest, litigation conduct, and attorney advertising compliance. She also represents lawyers facing disciplinary charges, ethics investigations, and other complaints. A leader with extensive law firm management experience, prior to joining McCarter & English, Diana served as the managing principal of the national law firm where she practiced for more than 25 years.
Her experience includes serving as lead counsel in a high-profile case addressing ethics and referral fees and handling a case before the New Jersey Appellate Division addressing the intersection of constitutional law and attorney regulation that resulted in a published opinion. Diana also provides ethics and compliance guidance to corporate clients.
An active leader in the New Jersey legal community, Diana currently serves as Second Vice President of the New Jersey State Bar Association and is slated to become the organization’s president in 2028. She served on the District XA Ethics Committee for 10 years, including serving as Chair from 2017-2019 after being appointed by the New Jersey Supreme Court. Diana is a past president of the New Jersey Women Lawyers Association, the Trial Attorneys of New Jersey, the Morris County Bar Association, and the Morris County Bar Foundation.
Diana regularly presents and writes on business litigation, legal ethics, and professional liability topics. She is the author of the New Jersey Chapter of The Law of Lawyer’s Liability: Fifty-State Survey of Legal Malpractice (ABA/First Chair Press),which provides an overview of the laws governing attorney malpractice in each state.
















