Mark L. Rienzi is President and CEO of Becket, a nonprofit, nonpartisan religious liberties law firm dedicated to protecting the free expression of all religious faiths. He is also a Professor of Law at the Catholic University of America, Columbus School of Law, where he is co-director of the Center for Religious Liberty, and has served as a Visiting Professor of Law at Harvard Law School. He teaches constitutional law, religious liberty, and evidence, and has been voted Teacher of the Year three times by the Law School’s Student Bar Association.

With the team at Becket, Mark has litigated and won an uninterrupted string of important First Amendment cases at the U.S. Supreme Court including Hosanna-Tabor v. EEOC (2012), Little Sisters of the Poor (2013), McCullen v. Coakley (2014), Hobby Lobby (2014), Wheaton College (2014), Holt v. Hobbs (2015), Zubik v. Burwell (2016), Our Lady of Guadalupe (2020), Little Sisters of the Poor (2020), Diocese of Brooklyn/Agudath Israel (2020), and Fulton v. Philadelphia (2021).

Mark’s scholarship on constitutional issues has appeared in a variety of prestigious journals including the Harvard Law Review, Stanford Law Review (online), and Notre Dame Law Review. He has been quoted on religious liberty issues in a variety of prestigious outlets, including the New York TimesWall Street JournalWashington Post, NPR, and he has been featured on the Kelly File, Fox News Sunday, Your World with Neil Cavuto, Geraldo at Large, CNN Tonight, CNN Live, Andrea Mitchell Reports, and Wall Street Journal Live.

Prior to joining Becket, Mark served as counsel for WilmerHale LLP and a law clerk to the Hon. Stephen F. Williams of the U.S. Court of Appeals for the D.C. Circuit. He earned his J.D. from Harvard Law School and B.A. from Princeton University, both with honors.