Justice Mariano-Florentino Cuéllar began serving on the California Supreme Court in January 2015. He was nominated by Governor Jerry Brown, confirmed unanimously by the Commission on Judicial Appointments, and retained by the voters for a full term in November 2014. Before serving on the Court, he was the Stanley Morrison Professor of Law and Professor (by courtesy) of Political Science at Stanford University. A member of the Stanford faculty since 2001, Cuéllar has written books and articles on administrative law and legislation, criminal law, international law, cyberlaw, immigration, public health law, 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 university-wide centers and 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, he worked at the White House as Special Assistant to the President for Justice and Regulatory Policy (2009-2010). He negotiated bipartisan food safety, tobacco, and criminal sentencing reform legislation; convened the White House's food safety working group and coordinated its response to the BP oil spill; expanded support for crime prevention and immigrant integration; and worked on enacting a bipartisan repeal of the military's Don't Ask/Don't Tell policy. He also co-chaired the U.S. Department of Education’s Equity and Excellence Commission (2011-2013), and before that, the presidential transition team on immigration, borders, and refugees (2008-2009). Currently, Cuéllar serves on the governing boards of Harvard University, the William & Flora Hewlett Foundation, the American Law Institute, and (as chair) the Center for Advanced Study in the Behavioral Sciences. 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. After law school, he began his career at the U.S. Treasury Department’s Office of Enforcement, working on disrupting financial and cross-border crime, 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. They have two children.