Bradley J. Hamburger is a litigation partner in the Los Angeles office of Gibson, Dunn & Crutcher. His practice focuses on class actions and complex litigation in both trial courts and on appeal. He is a member of the firm’s Class Actions, Appellate and Constitutional Law, and Labor and Employment practice groups.
Brad has represented clients in class actions and appeals across many areas of law, including employment, insurance, antitrust, consumer fraud, products liability, legal malpractice, and administrative law. He has briefed dozens of appeals, including cases in the United States Supreme Court, the Ninth Circuit, and the California Supreme Court, and has argued before the Ninth Circuit and the California Court of Appeal.
Brad has significant expertise in seeking interlocutory appellate review of class certification orders under Federal Rule of Civil Procedure 23(f), obtaining enforcement of arbitration agreements, and defending clients against representative actions under California’s Labor Code Private Attorneys General Act. Brad also regularly represents technology companies, and he has substantial experience litigating the application of Section 230 of the Communications Decency Act.
Brad has been ranked in the California Appellate Litigation category of the Chambers USA guide since 2023, recognized as a 2023 Client Service All-Star MVP by BTI Consulting Group, included in Lawdragon’s 2025 “500 Leading Litigators in America” guide, and named a 2025 Future Star by Benchmark Litigation. In 2022, Law360 recognized Brad as a Rising Star in the Class Action category, and the Los Angeles Business Journal named him to its “Thriving In Their 40’s: LA’s Leaders of Influence” list. The Daily Journal named Brad as one of the top 40 lawyers in California under 40 in 2021. Brad also was part of the team that obtained one of the Daily Journal’s Top Verdicts in California 2022, Ortiz v. Amazon.com LLC et al., Case No. 4:17-cv-03820-JSW (N.D. Cal.), and Top Appellate Reversals of 2021, Magadia v. Wal-Mart Associates, Inc., 999 F.3d 668 (9th Cir. 2021).
Recent Representative Matters Include:
- Obtained significant victory from the United States Supreme Court in action seeking over $20 billion in damages. Comcast Corp. v. Nat’l Ass’n of Afr. Am.-Owned Media, 589 U.S. 327 (2020).
- Secured important decision from the United States Supreme Court in high-profile case involving constitutional challenge to ordinances prohibiting camping on public property. City of Grants Pass, Oregon v. Johnson, 144 S. Ct. 2202 (2024).
- Obtained affirmance from the Ninth Circuit of summary judgment ruling in high stakes insurance coverage dispute relating to opioid distribution. AIU Ins. Co. v. McKesson Corp., 2024 WL 302182 (9th Cir. 2024).
- Convinced the Ninth Circuit to vacate critical-habitat designations under the Endangered Species Act. Ctr. for Biological Diversity v. United States Fish & Wildlife Serv., 67 F.4th 1027 (9th Cir. 2023).
- Secured affirmance from the Ninth Circuit of the denial of class certification in an insurance class action. Lara v. First Nat’l Ins. Co. of Am., 25 F.4th 1134 (9th Cir. 2022).
- Defeated motion for class certification and then secured a complete victory at trial in an employment misclassification action. Ortiz v. Amazon.com LLC, 2022 WL 1598968 (N.D. Cal. 2022).
- Successfully argued opposition to class certification motion in an employment class action. Mabanta v. Prime Now LLC, 2022 WL 1601415 (N.D. Cal. 2022).
- Obtained from the Ninth Circuit significant ruling regarding the scope of the exception to Section 230 of the Communications Decency Act for certain sex-trafficking claims. Does 1-6 v. Reddit, Inc., 51 F.4th 1137 (9th Cir. 2022).
- Obtained review from the Fourth Circuit of an order granting class certification in an antitrust class action, and then vacatur of the order. In re Zetia (Ezetimibe) Antitrust Litig., 7 F.4th 227 (4th Cir. 2021).
- Secured a new trial in a dispute with a former motor vehicle franchisee after a jury had awarded $256 million in damages, and affirmance of that ruling from the California Court of Appeal. Nissan Motor Acceptance Cases, 63 Cal. App. 5th 793 (2021).
Brad was a key member of both the trial and appeal teams in Chevron’s successful RICO action against a U.S. lawyer who was found to have fraudulently procured a multi-billion-dollar judgment against Chevron from an Ecuadorian court. After a seven-week bench trial in the Southern District of New York, the trial judge issued a 485-page decision in Chevron’s favor, the Second Circuit affirmed in full, and the Supreme Court denied certiorari. Chevron Corp. v. Donziger, 974 F. Supp. 2d 362 (S.D.N.Y. 2014), aff’d, 833 F.3d 74 (2d Cir. 2016), cert. denied, 137 S. Ct. 2268 (2017).
Brad’s publications include Article III Standing and Absent Class Members, 64 Emory L.J. 383 (2015) (with Theane Evangelis), and Three Myths About Wal-Mart Stores, Inc. v. Dukes (with Theodore J. Boutrous, Jr.). He also co-authored two chapters in the Third Edition of the American Bar Association’s A Practitioner’s Guide to Class Actions (2021), including the chapter on interlocutory appeals. He also routinely speaks at conferences on class actions and employment law.
Brad graduated cum laude from Harvard Law School in 2009. While at Harvard he served as co-Editor-in-Chief of the Harvard Journal of Law & Technology and was a member of the Board of Student Advisers. He graduated with honors from the University of California, Berkeley in 2004.
Prior to joining the firm, Brad served as a law clerk to the Honorable James V. Selna in the United States District Court for the Central District of California.
Brad is a member of the Board of Directors of the Friends of the Los Angeles County Law Library. Before entering law school, Brad taught middle school mathematics in New York City as a Teach for America corps member.
Capabilities
- Class Actions
- Appellate and Constitutional Law
- Insurance and Reinsurance
- Labor and Employment
- Law Firm Defense
- Litigation
- Technology Litigation
- Transnational Litigation
- Trials
Credentials
Education:
- Harvard University - 2009 Juris Doctor
- University of California - Berkeley - 2004 Bachelor of Arts
Admissions:
- California Bar
Clerkships:
- USDC, Central District of California, Hon. James V. Selna, 2009 - 2010