Peter B. Siegal is an appellate partner in Norton Rose Fulbright's Washington, D.C. office. His practice focuses principally on complex, high-stakes litigation in the Supreme Court of the United States and the federal courts of appeals, where he routinely argues and wins high-dollar-value cases in a broad range of subject areas. Peter also often practices before federal agencies and trial courts, where he is regularly called upon to develop case-dispositive strategy and oversee briefing in his clients’ most significant matters. Peter has been recognized as one of the leaders of the appellate bar's next generation by an array of the Country's top legal publications, including Super Lawyers Magazine (which has honored him as a "Rising Star" eight years running), Benchmark Litigation (which lists him as one of the top lawyers 40 or younger nationwide), and the National Law Journal (which lists him as one of Washington, D.C.'s top lawyers 40 or younger in any practice). As of 2024, Peter is also ranked among the top Federal Circuit practitioners by Patexia, which analyzes patent-related appeals from 2019 through 2023.

Peter also maintains an active pro bono practice and is a past recipient of the Jaworski Award, which is Norton Rose Fulbright's highest pro bono honor. In addition, he is a participant in The Appellate Project's Mentorship Program, which is the first national effort focused on empowering law students of color to pursue appellate work, and a member of the Edward Coke Appellate Inn of Court.

Peter joined Norton Rose Fulbright in 2018, after practicing at a litigation boutique in Washington, D.C., and serving as a law clerk to the Honorable William J. Kayatta, Jr., of the United States Court of Appeals for the First Circuit. He lives in Bethesda, Maryland, with his wife and young daughter.