William H. 'Chip' Mellor III (1949–2024) was an American libertarian lawyer and co-founder of the Institute for Justice (IJ), a public interest law firm dedicated to defending economic liberty, property rights, school choice, and free speech. Born in Knoxville, Tennessee, he earned a B.A. from Ohio State University in 1973 and a J.D. from the University of Denver Law School in 1977. Mellor began his career at the Mountain States Legal Foundation (1979–1983), serving as acting president around 1982, followed by a role as Deputy General Counsel for Legislation and Regulations at the U.S. Department of Energy during the Reagan administration. From 1986 to 1991, he was president of the Pacific Research Institute in San Francisco. In 1991, he co-founded IJ with Clint Bolick and served as its founding president and general counsel until 2016, when he became chairman of the board—a position he held until his death. Under his leadership, IJ achieved landmark victories, including breaking Denver's 50-year taxi monopoly, ending Tennessee's funeral industry casket sales monopoly, defending New Jersey's welfare reform, arguing 12 U.S. Supreme Court cases (winning 10), and supporting District of Columbia v. Heller. He established the IJ Clinic on Entrepreneurship at the University of Chicago and co-authored The Dirty Dozen: How Twelve Supreme Court Cases Radically Expanded Government and Eroded Freedom (2008) with Robert A. Levy. Mellor received the Bradley Prize in 2012 and served on the board of the Property and Environment Research Center (PERC). He resided in Moab, Utah, and died from leukemia on October 11, 2024, surrounded by family.