O’Melveny Worldwide

Supreme Court & Appellate Litigation

O’Melveny’s appellate team brings creative strategic thinking, persuasive legal writing, and skilled oral advocacy to solve problems for clients at all levels of the judiciary, federal and state.

O’Melveny’s appellate team brings creative strategic thinking, persuasive legal writing, and skilled oral advocacy to solve problems for clients at all levels of the judiciary, federal and state.

With experience arguing hundreds of cases before appellate courts, O’Melveny’s Supreme Court and Appellate Litigation practice solves high-stakes problems for clients. Our track record before the US Supreme Court, where O’Melveny argues cases almost every term and has filed merits and amicus briefs in scores more, includes numerous precedent-setting victories. And our lawyers successfully litigate in every federal court of appeals as well as state supreme and intermediate courts nationwide. 

Working with clients at all stages of litigation—from dispositive motions in trial court to merits briefing and argument in courts of last resort—we develop and present cutting-edge legal arguments that tackle issues as a matter of first principles and persuade courts to rebuild the law from the ground up. Our team includes high-ranking veterans of the US Solicitor General’s office and other Department of Justice divisions, as well as former clerks for Supreme Court Justices and judges on every US federal court of appeals. We work in unison with litigators across the firm’s practice and industry groups, giving clients the benefit of our collective experience in virtually every area of law. 

Supreme Court Practice. Our bench of veteran Supreme Court lawyers has collectively argued more than 150 cases before the Justices, often appearing multiple times a Term. A recent study pronounced O’Melveny’s briefs the “most influential” in helping to shape the Court’s analysis.

We have extensive experience with every aspect of Supreme Court practice—from briefing and arguing merits cases, to seeking and opposing certiorari on behalf of clients, to formulating and executing amicus curiae strategy and representing amici at all stages. Our team draws on the talents of accomplished appellate advocates including Practice Chair Jonathan Hacker, Anton Metlitsky, and Jeffrey Fisher, who has argued 40 cases in the Supreme Court and holds a place among the National Law Journal’s “100 Most Influential Lawyers” in America.

Appellate Practice. Appellate litigation at O’Melveny extends far beyond the Supreme Court. We have successfully argued cases in every federal appellate circuit and state courts of last resort nationwide, including courts where the most significant business cases are litigated such as the US Courts of Appeals for the D.C., Second, Ninth, and Federal Circuits; the California Supreme Court and Courts of Appeal; the New York Court of Appeals and Appellate Division; and the Delaware Supreme Court.

We file briefs in state and federal trial and appellate courts and formulate strategy and arguments seeking and opposing discretionary appeals from higher courts, always bearing in mind the appellate lawyer’s primary task of “translating” complex technical questions to the generalist judges who will review and decide them.

Trial Court Practice. Our appellate work often starts long before the filing of any appeal—or even before the filing of an answer. Our appellate lawyers work closely with clients and trial teams at every step of a litigation to identify and craft arguments for dismissal or summary judgment and to draft motions of all kinds before, during, and after trial.

We have particular experience serving as embedded trial counsel in high-exposure, complex civil cases in various state court systems. We work closely with trial counsel to ensure that important appellate issues that arise during trial are properly framed and preserved for appeal, and help shape the case in a manner most favorable to achieving our clients’ desired outcomes.

Whatever the venue, issue, or subject matter, the skill and experience of our appellate lawyers ensures that we can provide forceful advocacy, nuanced advice, or creative solutions to meet our clients’ needs.

American Airlines

Successfully defended American in the Fifth Circuit against an ERISA lawsuit alleging its 401(k) plan offered an investment option that benefited the company more than its employees. Not only did the win allow our client to avoid a multimillion-dollar settlement and potentially adverse verdict, but it ensured that American could continue offering a popular Credit Union Option to its participants.

Airlines for America

Secured a favorable outcome related to the government’s setting of fee levels for inspection programs of goods shipped through U.S. ports. Despite a difficult standard of review applicable to agency challenges, the D.C. Circuit ruled in our favor on an issue crucial to our clients, holding that the Department of Agriculture cannot continue to collect fees to fund a reserve after a certain date.

Century 21 Real Estate

Secured a landmark victory in a California appellate court for Anywhere Real Estate’s subsidiary, in a statewide representative action brought on behalf of real estate agents who alleged they were misclassified under California law as independent contractors rather than employees. The case challenged the constitutionality of California statute AB-5, aimed at reclassifying gig workers as employees.

Century Indemnity Company

Prevailed in a significant Second Circuit decision overruling controversial precedents that had capped reinsurers’ liability for defense costs. Under the Second Circuit’s 1990 Bellefonte rule, the total amount of reinsurance coverage presumptively included defense costs, even if the reinsured policy paid defense costs in addition to its indemnity limits. We persuaded the court to take another look at this widely criticized precedent and adopt the common-sense rule that reinsurance certificates generally treat payment of defense costs the same way the reinsured policy treats them.

China Agritech

In China Agritech Inc. v. Michael H. Resh et al., we obtained a unanimous Supreme Court victory against efforts to toll the statute of limitations for absent class members, imposing a check on serial class actions. In a rare accomplishment in securities litigation, O’Melveny twice defeated motions for class certification and secured dismissal of the third case on statute of limitations grounds. When the Ninth Circuit reversed that dismissal, the Court reinstated our victory, holding that putative class members who decline to join an existing suit or promptly file an individual action may not commence a class action anew beyond the statutory limitations period.

Chubb Group

In a landmark Delaware Supreme Court ruling, O’Melveny secured a decision that Chubb was not obligated to defend Rite Aid Corp. against lawsuits accusing the drugstore chain of contributing to the nationwide opioid epidemic. 

City of Austin

In City of Austin, Texas v. Reagan National Advertising of Texas Inc., we secured a significant victory for municipalities with sign ordinances. Persuading the Supreme Court, we successfully defended the City of Austin’s billboard regulation, which prohibits the digitization of off-premises signs. The ruling upheld the measure as content-neutral, avoiding a First Amendment violation.

David Dubin

In a unanimous ruling for our client, the Supreme Court rejected the government’s interpretation of the federal “aggravated identity theft” statute, which had led to a two-year enhancement to his Medicaid fraud conviction. Our argument, accepted by the Court, clarified that the identity-theft enhancement only applies when the misuse of someone’s name is central to the fraud, not merely incidental.


Achieved a complete victory for Google in a 13-year patent dispute with a hardware manufacturer, affirmed by the Federal Circuit Court of Appeals, invalidating dozens of patent claims across four patents. This landmark decision concluded protracted litigation that began in 2010, involving multiple reexaminations and appeals, and resulted in the invalidation of all claims protected Google from further infringement claims.

Industry-leading pharmaceutical company

Convinced the Oklahoma Supreme Court to reverse a trial court’s ruling that called for our client to pay US$465 million for nuisance abatement.

Louis Ciminelli

Secured victory for client Louis Ciminelli before the Supreme Court in overturning a federal wire fraud conviction based on flawed “right to control” theory. The Court unanimously rejected the theory, ruling it does not constitute a “traditional property interest” criminalized under federal fraud statutes.

Kesha Rose Sebert

In a high-profile appeal, New York’s highest court sided with our client Kesha, reversing two lower court decisions. The court determined that music producer Dr. Luke was a ‘limited-purpose public figure’ due to his celebrity status. This ruling subjected the producer’s defamation claims to a higher standard of proving actual malice, making it more challenging for him to demonstrate that Kesha defamed him by publicly accusing him of sexual assault. 


Secured a victory for Meta when the Ninth Circuit affirmed a district court ruling refusing to find Israeli spyware company NSO Group immune from litigation over an alleged hack of WhatsApp. The US Supreme Court turned away NSO’s appeal of the decision that the lawsuit could move forward, after asking the U.S. Solicitor General to weigh in on the arguments presented.

Puerto Rico Fiscal Agency and Financial Advisory Authority

In Financial Oversight and Management Board for Puerto Rico v. Aurelius Investment, LLC, we secured a unanimous Supreme Court victory for our client Puerto Rico Fiscal Agency and Financial Advisory Authority against a creditor’s suit alleging that President Obama violated the Constitution’s Appointments Clause in making appointments to the island’s financial oversight board without the Senate’s advice and consent. The case threatened to nullify much of the work the board has done to help restructure debt and bring about other reforms.

Samsung and LG Electronics

Secured precedent-setting victories in the Federal Circuit on motions to transfer patent cases out of the Western District of Texas, weakening patent plaintiffs’ ability to handpick their venues and cementing our reputation as a leading force in the area.

Sirius XM

Obtained a series of precedent-setting victories at the Ninth Circuit and elsewhere on a critical issue in the music industry, allowing Sirius XM and others to play music from recordings created before 1972 for the public without paying record companies.

United Airlines

Convinced the Seventh Circuit to affirm a decision granting summary judgment to our client in a certified pilot class action alleging the airline denied sick and vacation time, as well as full pension payments, to pilot employees on military leave—a purported violation of the Uniformed Services Employment and Reemployment Rights Act (USERRA), the federal statute that governs private employment of military servicemembers and reservists.

Representative Clients
American Airlines
Chubb Group
Fidelity Management Trust Co.
Johnson & Johnson
Samsung Electronics
The Walt Disney Company
Twentieth Century Fox
United Airlines

“Brilliant lawyers, amazing writers and former Supreme Court law clerks.” 

—Client Testimonial, The Legal 500 US

“There’s tremendous depth and talent there; it’s a spectacular group and appellate practice.”

—Client Testimonial, Chambers USA

“This is the smartest group of attorneys with whom I have worked, and an equally humble group as well. They collaborate and partner with clients to reach the best outcomes.”

—Client Testimonial, The Legal 500 US

“They take on a lot of difficult and unusual cases, the brief writing is always very strong and they're extremely reputable - they play straight with the courts and have a good reputation with the judges.” 

— Client Testimonial, Chambers USA

“Their appellate practice is amazing and so is the quality of the team. The value of working with them is immeasurable and their written work and oral advocacy is impeccable.”

—Client Testimonial, Chambers USA

“O’Melveny calls upon a robust group of respected appellate experts to offer broad strengths in an array of business law and wider constitutional disputes.”

—Chambers USA

Appellate Hot List

—National Law Journal (2008-2013, 2018-2019, 2022-2023)

Appellate Practice Group of the Year

—Law360 (2020)