Roger Pilon (born November 28, 1942) is an American legal scholar, philosopher, and libertarian theorist renowned for his work on constitutional law, individual rights, limited government, originalist interpretation, civil liberties, and the rule of law. He is a senior fellow in the Cato Institute's Center for Constitutional Studies, which he founded in 1989 and directed until 2019. Pilon served as Cato's vice president for legal affairs from 1999, inaugural holder emeritus of the B. Kenneth Simon Chair in Constitutional Studies (established 1998), and founding publisher emeritus of the Cato Supreme Court Review (launched 2001). Prior to Cato, he held five senior positions in the Reagan administration, including roles in the Departments of State and Justice, such as Director for Asylum Policy at the Department of Justice. Pilon has testified before Congress on issues like separation of powers and property rights, contributed to academic journals and media outlets, and collaborated professionally with figures like Leonard Leo in conservative legal circles. He earned a B.A. from Columbia University, an M.A. and Ph.D. from the University of Chicago, and a J.D. from George Washington University School of Law. Active in public discourse through C-SPAN appearances, Federalist Society events, writings, and a presence on X (formerly Twitter) as @Roger_Pilon, Pilon has influenced debates on judicial roles, religious freedom, and federalism, often presenting complex legal ideas accessibly to diverse audiences. He is married to Juliana Geran Pilon.