Mark Fleming is Co-Chair of WilmerHale’s Appellate and Supreme Court Litigation Practice. Mark’s broad-based appellate experience covers numerous subject areas, ranging from patent law, securities, and complex business disputes to real estate, antitrust and tax. He has appeared in more than 300 appellate cases and personally presented oral argument in 72 of them, including eight before the Supreme Court of the United States.  He has also argued before the Supreme Judicial Court of Massachusetts, the Massachusetts Appeals Court, and the First, Second, Third, Eighth, Ninth, Tenth, Eleventh, Federal, and District of Columbia Circuits.  His notable representations include arguing three complex appeals for different clients in a single week in November 2019; winning vacatur of the largest patent infringement judgment in history ($2.7 billion) in June 2022; and winning three favorable Federal Circuit decisions within a single week in June 2025, overturning judgments totaling over $500 million.  At the BBA, Mark recently Co-Chaired the BBA’s Task Force on Reproductive Rights. He has formerly been the Co-Chair of the International Law Section, Chair of the Amicus Committee, Chair of the Beacon Award Selection Committee, and a member of the BBF Fellows Committee. Mark served as a law clerk to the Honorable David H. Souter of the Supreme Court of the United States, the Honorable Michael Boudin of the First Circuit, and the Honorable John C. Major of the Supreme Court of Canada. Between 2023 and 2025, he served as Vice Chair of the Massachusetts Judicial Nominating Commission, which vets candidates for judicial office in Massachusetts.  He is a former member the Massachusetts Joint Bar Committee, and currently serves on the Advisory Board of the South Asian Bar Association of Greater Boston. He is a graduate of University of King’s College/Dalhousie University and Harvard Law School.