Jennifer Lee "Jenn" Mascott (née Miller; born 1976) 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).
- Gender
- Female
- Race
- White
Prior employment
- Catholic Law SchoolAssociate professor of law · 2024–2025
- ↳founder and director, Separation of Powers Institute and Student Litigation Clinic · 2024–2025
- White House Counsel's OfficeSenior counsel · 2025
U.S. Department of Justice2019–2021- ↳deputy assistant attorney general, Office of Legal Counsel · 2019–2020, 2020–2021
- ↳associate deputy attorney general · 2020–2021
- Private practice, Arlington, Virginia2017–2019
- George Washington University Law School2011–2013, 2015–2017
- ↳professorial lecturer in law · 2011, 2012, 2012–2013, 2015
- ↳Olin/Searle Fellow · 2016–2017
Olin/Searle Fellow · 2015–2017
Law clerk , Hon. Clarence Thomas · 2008–2009
Law clerk , Hon. Brett M. Kavanaugh · 2006–2007- George Mason University Antonin Scalia Law School, 2017-2024 (on leave 2019-2021)Assistant professor of law
- ↳co-director, Administrative Law and Supreme Court Clinics · 2017–2018
- ↳faculty director and founder, Separation of Powers Student Litigation Clinic · 2021–2024
- ↳co-executive director, C. Boyden Gray Center for the Study of the Administrative State · 2021–2024
Appointments
2025–present · Appointed by Donald J. Trump (Republican)
Education
- University of MarylandB.S.
J.D. · 2006