David Casazza is a senior associate in the Washington, D.C. office of Gibson, Dunn & Crutcher. He practices in the firm’s Appellate and Constitutional Law, and Administrative Law and Regulatory Practice Groups.

David has represented clients in appellate and regulatory litigation before the Supreme Court of the United States, federal appellate courts, and federal district courts. These cases have involved a wide range of subjects including separation of powers, federal rulemaking challenges, business reorganization, anti-terrorism claims and foreign sovereign immunity, energy infrastructure permitting, and a variety of First Amendment speech and religious liberty claims. He has also represented clients in complex litigation, including large class actions, antitrust, and racketeering cases. He is named in Best Lawyers: Ones to Watch® in America for Appellate Practice, and Administrative / Regulatory Law, and has been listed in the publication since 2021.

He graduated magna cum laude from Harvard Law School, where he served as a Managing Editor for the Harvard Journal of Law and Public Policy and as Executive Vice President of the Harvard Federalist Society. David received a Bachelor of Arts, magna cum laude, in history from Princeton and a Master of Arts in history from the Johns Hopkins University.

David served as a law clerk to Justice Samuel Alito on the Supreme Court of the United States and for Judge Jennifer Walker Elrod on the United States Court of Appeals for the Fifth Circuit.

He is a member of the bars of New York and the District of Columbia and is admitted to practice before the Supreme Court of the United States, the United States Courts of Appeals for the D.C., Second, Third, Fourth, Fifth, and Ninth Circuits and in the United States District Court for the District of Columbia.