David W. Casazza

David Casazza is a partner in the Washington, D.C. office of Gibson Dunn. He practices in the firm’s Appellate and Constitutional Law and Administrative Law and Regulatory Practice Groups. He is a member of the firm’s Hiring Committee.

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, anti-terrorism claims and foreign sovereign immunity, energy infrastructure permitting, and a variety of First Amendment speech and religious liberty claims. He routinely represents clients in bankruptcy and restructuring appeals presenting complicated or novel issues. He has also represented clients in complex litigation, including large class actions, antitrust, and racketeering cases.

David is a public member of the Administrative Conference of the United States, which advises the federal government on questions of administrative law and procedure. He teaches appellate advocacy as a Professorial Lecturer on Law at the George Washington University Law School. He is a member of the Edward Coke Appellate Inn of Court and is a former Temple Bar Scholar of the American Inns of Court. 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.

Representative matters include:

• Olivier v. City of Brandon, 146 S. Ct. 916 (2026): Represented petitioners obtaining unanimous victory in Supreme Court in religious liberty and free speech case concerning access to federal courts.
• CC/Devas (Mauritius) Ltd. v. Antrix Corp., 605 U.S. 223 (2025): Represented petitioners obtaining unanimous victory in Supreme Court in international arbitration enforcement action addressing personal jurisdiction and sovereign immunity.
• Truck Insurance Exchange v. Kaiser Gypsum Co., 602 U.S. 268 (2024): Represented petitioners obtaining unanimous victory in Supreme Court rejecting decades-old bankruptcy precedent and confirming broad participatory rights of interested parties under the Bankruptcy Code.
• Amazon.com v. WDC Holdings LLC, 155 F.4th 313 (2025): Represented major technology company in reviving racketeering and other claims on appeal before Fourth Circuit in case relating to alleged real estate kickback scheme.
• Truck Insurance Exchange v. Kaiser Gypsum Co., 134 F.4th 185 (2025): Argued on behalf of insurer in Fourth Circuit in appeal challenging terms of Chapter 11 plan of asbestos tort debtor.
• End Citizens United v. Federal Election Commission, 69 F.4th 916 (2023): Argued as court-appointed amicus in D.C. Circuit in case addressing separation of powers and administrative law procedures under the Federal Election Commission Act.
• Ballentine v. Broxton, No. 22-50437 (2023): Argued on behalf of prisoner in Fifth Circuit obtaining two unanimous reversals reviving civil rights claims.
• Ad Hoc Committee of Holders of Trade Claims v. Pacific Gas & Electric, 46 F.4th 1047 (2022): Represented creditor group in Ninth Circuit obtaining recognition of creditors’ right to repayment of interest accrued during Chapter 11 proceeding. Successfully opposed petition for Supreme Court review.

David 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. He 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.

Capabilities

• Appellate and Constitutional Law
• Administrative Law and Regulatory Practice
• Business Restructuring and Reorganization

Credentials

Education:

• Harvard University - 2015 Juris Doctor
• Johns Hopkins University - 2012 Master of Arts
• Princeton University - 2010 Bachelor of Arts

Admissions:

• District of Columbia Bar
• New York Bar

Clerkships:

• US Supreme Court, Hon. Samuel A. Alito Jr., 2018 - 2019
• US Court of Appeals, 5th Circuit, Hon. Jennifer Walker Elrod, 2015 - 2016