Justice Mariano-Florentino Cuéllar was nominated by Governor Jerry Brown and began serving on the California Supreme Court in January 2015. 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, 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. 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 served on the Obama-Biden transition team (2008-2009), and later, co-chaired the U.S. Department of Education’s Equity and Excellence Commission (2011-2013). Currently, Cuéllar is 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 California's 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 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.