Associate Justice Mariano-Florentino Cuéllar

Justice Mariano Florentino Cuellar

Justice Mariano-Florentino Cuéllar began serving on the California Supreme Court in January 2015. Previously he was the Stanley Morrison Professor of Law and Professor (by courtesy) of Political Science at Stanford University. A Stanford faculty member since 2001 and a fellow of the American Academy of Arts and Sciences, Cuéllar is a scholar of public law and institutions whose books and articles explore problems in administrative law and legislation, cyberlaw, criminal justice, public health law, international law and security, immigration, and the history of institutions.

Between 2004 and 2015, Cuéllar also held leadership positions at Stanford’s Freeman Spogli Institute for International Studies. As Institute director, he supervised twelve research centers and educational programs addressing international affairs, governance and development, and health policy. During his tenure leading the Institute and, earlier, its Center for International Security and Cooperation, Cuéllar grew the Institute’s faculty, expanded Stanford’s role in nuclear security research, launched university-wide initiatives on global poverty and cyber security, and broadened opportunities for student and faculty research abroad.

While on leave from Stanford, Cuéllar worked at the White House as Special Assistant to the President for Justice and Regulatory Policy (2009-2010). In this capacity, he led the Domestic Policy Council staff responsible for civil and criminal justice, public health law and policy, and immigration; negotiated bipartisan food safety, tobacco, and criminal sentencing reform legislation; expanded support for crime prevention and immigrant integration; and worked to enact the bipartisan repeal of the military's Don't Ask/Don't Tell policy. He also led the Presidential Transition Task Force on Immigration (2008-2009), and later, co-chaired the U.S. Department of Education’s Equity and Excellence Commission (2011-2013). Currently, Cuéllar is on the boards of Harvard University, the Hewlett Foundation, the American Law Institute, and (as chair) the Center for Advanced Study in the Behavioral Sciences, AI Now, and Stanford Seed.  Within the California judiciary, he leads the Language Access Implementation Task Force.

A naturalized U.S. citizen born in Northern Mexico, Cuéllar graduated from Calexico High School in California’s Imperial Valley. He received a B.A. from Harvard magna cum laude, a J.D. from Yale Law School, and a Ph.D. in Political Science from Stanford. He began his career at the U.S. Treasury Department's Office of Enforcement and clerked for Chief Judge Mary M. Schroeder of the U.S. Court of Appeals for the Ninth Circuit. He is married to Judge Lucy H. Koh of the U.S. District Court for the Northern District of California.