Jennifer Lee "Jenn" Mascott is an American lawyer and jurist serving as a United States circuit judge of the United States Court of Appeals for the Third Circuit. Prior to her judicial appointment, Mascott was a law professor whose research focused on separation of powers and litigation. She taught at the Columbus School of Law of Catholic University of America (2025), the Antonin Scalia Law School of George Mason University (2017–2024), and the George Washington University Law School (2011–2017).