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California Appellate

Arnold & Porter has broad experience in the California appellate courts and the federal appellate courts, with particular focus on the Ninth Circuit. Our deep bench has been repeatedly recognized for its excellence and our appellate lawyers are active leaders in state and national appellate associations. Our team includes appellate specialists certified by the State Bar of California, members of the selective California Academy of Appellate Lawyers, members of the invitation-only American Academy of Appellate Lawyers, former clerks at the Ninth Circuit, and the former chair of the State Bar of California. We bring thorough, careful, and objective analysis, systematically identifying not only winning arguments but also challenges that must be overcome. Through lively writing and compelling storytelling, we understand that a sympathetic factual presentation can be just as important to success as a powerful legal argument.

“The firm provides strong work at every level from associate to the head of the group.” – Chambers USA, California Appellate
“Arnold & Porter's bench is excellent in every way.” — Chambers USA, California Appellate

Experience Highlights

  • Planned Parenthood in a successful appeal to the Ninth Circuit regarding a multi-million jury verdict involving issues under the First Amendment, RICO, and state and federal wiretapping statutes, as well as common-law claims for fraud, trespass, and breach of contract. Planned Parenthood Federation of America Inc. v. Newman (9th Cir. 2022)

  • DaVita Inc. in successful Ninth Circuit appeal involving Medicare statutes. Secured pathbreaking decision holding that medical service providers can sue health plans for discriminating against patients needing dialysis. DaVita Inc. v. Virginia Mason Memorial Hospital (9th Cir. 2020)

  • Oakland Raiders in winning dismissal of an antitrust challenge to the Oakland Raiders' relocation to Las Vegas and preserving the judgment on appeal to the Ninth Circuit. City of Oakland v. Oakland Raiders (9th Cir. 2021)

  • Bristol Myers-Squibb in a First Amendment challenge to civil enforcement action brought by Hawaii Attorney General. Bristol Myers-Squibb v. Connors (9th Cir. 2020)

  • One of the nation’s largest concert promotion businesses in obtaining affirmance of judgment protecting our client’s ownership interests. (Cal. Ct. App. 2021)

  • ASCAP, America's oldest Performing Rights Organization in litigation to enforce the music copyrights of its composer, songwriter, and publisher members, in hundreds of cases over more than 25 years, including judgment for willful copyright infringement at a federal jury trial against owners of multiple radio stations, affirmed on appeal. WB Music Corp. v. Stolz (9th Cir. 2020)

  • Dr. Michael Williams in securing reversal of anti-SLAPP dismissal, including first ruling that a case may be dismissed without prejudice in response to an anti-SLAPP motion, followed by a new action removing allegations of protected activity. Williams v. Doctors Medical Center (Cal. Ct. App. 2024)

  • Experian, as lead appellate counsel, in copyright and trade secret matter involving issue of copyrightability and trade secret protection of marketing databases. Experian Information Solutions, Inc. v. Nationwide Marketing Services, Inc. (9th Cir. 2019)

  • Law firm in successfully defending summary judgment in favor of client in malpractice and alleged elder abuse action (Cal. Ct. App. 2021)

  • DCR Workforce, a cloud-based software company, in a Ninth Circuit appeal relating to a contract dispute with a software company. DCR Workforce, Inc. v. Coupa Software, Inc. (9th Cir. 2022)

Key Contacts

Sean M. SeLegue
Sean M. SeLegue
San Francisco
+1 415.471.3169
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Related Services


  • Chambers USA
    Litigation: Appellate – California (2024)
    Appellate Law – Nationwide (2024)
  • The National Law Journal
    "Appellate Hot List" (2023), recognized for the 9th year
  • Law360
    "Practice Group of the Year" (2023)
    "Firms That Dominated the Federal Circuit"
    Litigation Powerhouse
  • BTI Consulting Group
    Most Feared in Litigation (2023)
  • U.S. News & World Report and Best Lawyers
    "Best Law Firms" for Appellate Practice – San Francisco, Colorado, Washington, D.C., National, New Jersey (2024)
    "Best Law Firms" for Bet-the-Company Litigation – San Francisco, Chicago, Colorado (2024)
  • The Legal 500 US
    Appellate: Courts of Appeals (2023)
    Appellate: Supreme Courts (states and federal) (2023)
  • Financial Times Innovative Lawyers
    “Standout” Innovative Lawyers in the Supreme Court (2023)
  • Washingtonian Magazine
    "Top Lawyers" Supreme Court (2022)
  • LMG Life Sciences
    Impact Case of the Year: Hologic v. Minerva (U.S. Supreme Ct. 2021)