O’Melveny Worldwide

David Marroso is a first-chair trial lawyer and the head of O’Melveny’s firmwide General Litigation Practice. David represents clients in high-stakes antitrust, contract, criminal, environmental, insurance, intellectual property, and real property matters. His clients are some of the most sophisticated and well-known companies in apparel, consumer goods, financial services, media and entertainment, private equity, and real estate.

Clients describe David as a “brilliant litigator,” “one of the smartest lawyers” they know, and among “the best legal minds” in the country, according to The Legal 500, Chambers USA, and Billboard. Outside of the courtroom, David prides himself on forging lasting and trusting relationships with his clients, which they’ve described as “more like a partnership than a work-for-hire endeavor.” 

David has been honored as a “Litigation Star” (Benchmark), as one of music’s top litigators (Billboard), and as leading entertainment litigator three years in a row (Variety). Chambers USA has named David a Recognized Practitioner in General Litigation as well as for Media & Entertainment Litigation in California. He writes and lectures regularly about legal issues, ranging from fair use of photographic images to music copyright law to the boundaries of zealous advocacy.  

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Lead Counsel Experience

  • Lead counsel for real estate consultant The Townsend Group in a billion-dollar fiduciary duty lawsuit brought by Dallas Police and Fire Pension System 
  • Lead counsel for Lennar Corp., the largest homebuilder in the US, in a sprawling environmental case alleging cleanup fraud by a Navy contractor at the former Hunters Point shipyard in San Francisco
  • Co-lead counsel in a precedent-setting music antitrust lawsuit on behalf of Irving Azoff’s Global Music Rights organization—which represents songwriters from Drake to Bruce Springsteen—against the Radio Music Licensing Committee
  • Lead counsel for ThreeSixty Brands Group in trademark and contract lawsuits over licensing rights to the iconic Sharper Image brand
  • Lead trial counsel on behalf of championship boxers Tyson Fury and Manny Pacquiao and boxing promotion giant Top Rank in a variety of contractual matters, including a precedent-setting knockout victory against claims that the 2015 “Fight of the Century” fell short of expectations 
  • Lead trial counsel for Lennar Corp. in US$500 million trademark lawsuit brought by media company 
  • Lead counsel for Madison Square Garden in its successful defense against a highly publicized lawsuit brought by a boxer severely injured while participating in a match at “The Garden”
  • Lead counsel for hospitality whiz Sam Nazarian and his company sbe entertainment in US$50 million trademark lawsuit over the rights to the mark “Luxe”
  • Lead counsel for Lee Yong-dae, South Korean badminton gold medalist, in a successful appeal to the Court of Arbitration of Sport reversing a doping suspension
  • Lead counsel for movie theater giant AMC Entertainment in a US$200 million lawsuit concerning the technology behind buying movie tickets online
  • Trial counsel for global apparel brand Guess? Inc. in trademark dispute with Gucci
  • Lead counsel for global agricultural giant Agrium, Inc. (now Nutrien) in a US$100+ million breach of contract and interference lawsuit involving “organic” fertilizer; and co-lead counsel for Agrium in a $500 million antitrust conspiracy lawsuit involving the fertilizer component potash
  • Trial counsel for Hollywood Foreign Press Association in dispute over rights to the Golden Globes against dick clark production
  • Lead counsel for TOKYOPOP, Inc., one of the world’s top producers of anime, in successful arbitration against primary distributor for breach of contract and fraud

Other Experience

Entertainment and Media

  • Fox Corp. in precedent-setting successful litigation against Netflix for poaching key executives
  • The Walt Disney Company in profit participation, First Amendment, and defamation disputes
  • Miramax Films in a royalty and accounting dispute involving a portfolio of popular motion pictures
  • Motown Records and founder Berry Gordy in successful malicious prosecution and royalty dispute lawsuit against former Motown songwriters and producers
  • Rimrock Capital in connection with accounting and royalty disputes
  • Sony Pictures in a credit and rights dispute concerning the movie “Spider-Man”
  • Colorado detective and author Steve Thomas in a libel lawsuit brought by the family of JonBenet Ramsey
  • Italian moviemaker Vittorio Cecchi Gori in a high-profile “palimony” case
  • The Weinstein Company on various disputes concerning economics and credit rights to popular films


  • Numerous boxers and mixed martial artists, including Antonio “the Tijuana Tornado” Margarito, Miguel Angel Cotto, and Timothy “Desert Storm” Bradley in contract and regulatory matters before State Athletic Commissions
  • Major League Baseball player in business dispute with music agent
  • HBO in disputes concerning the broadcast of championship fights

Intellectual Property 

  • ABC, Inc. in a first-of-its-kind copyright class action involving the use of music on daytime television
  • DGE Entertainment in various intellectual property matters
  • Guess? Inc. in multiple trademark matters, including in an arbitration against former licensees of the “Baby Guess” line
  • Chinese manufacturing giant Midea in intellectual property and breach of contract dispute against a domestic distributor of products
  • Sirius XM satellite in lawsuits about a claimed performance right for sound recordings made before 1972

Environmental / Regulatory

  • Colony Capital (now Digital Bridge) and portfolio companies in matters ranging from a tax investigation in Sardinia to ERISA claims related to sale of an investment in a gaming property 
  • ACE Insurance in separate coverage matters originating from environmental contamination at California sites
  • Agrium, Inc. in connection with environmental monitoring and cleanup and cost recovery actions in the Western United States


  • Represent several national employers in labor and employment class actions
  • Lead lawyer in internal investigations concerning allegations of executive misconduct


  • Amylin Pharmaceuticals in sweeping class action filed concerning groundbreaking insulin medication Byetta
  • Pharmaceutical service provider Omnicare in a dispute related to its acquisition of major California distributor of medications


  • Jeffrey Skilling, the former CEO of Enron, in his criminal trial, at sentencing, and on appeal
  • City of Redondo Beach in obtaining a conviction in a week-long criminal jury trial
  • The Marciano Brothers, the founders of Guess, in prosecuting a scheme involving a Ponzi scheme of wine futures


Bar Admissions

  • California 

Court Admissions

  • US Supreme Court
  • US Court of Federal Claims
  • US Court of Appeals, Fourth, Fifth, Eighth, Ninth, and Eleventh Circuits
  • US District Court, Northern, Eastern, Central, and Southern Districts of California


  • Harvard Law School, J.D., 2000: magna cum laude
  • University of Nevada at Reno, B.S., Criminal Justice, 1996: magna cum laude

Honors & Awards

  • Ranked by Chambers USA for Media & Entertainment: Litigation (2021-2024) and named a “Recognized Practitioner” for Litigation: General Commercial in California (2017-2018)
  • Recognized by Benchmark Litigation as a Litigation Star in Entertainment, Commercial, and Media (2024)
  • Named to Top Music Lawyers List by Billboard (2022-2024)
  • Named a Local Litigation Star for General Commercial, and Media & Entertainment by Benchmark Litigation (2019-2023)
  • Recommended by The Legal 500 US for Sports (2017 & 2020-2021); and for Media and Entertainment: Litigation (2022-2023)
  • Named to Variety’s Legal Impact Report (2019-2020)

Professional Activities

Recent Thought Leadership

  • “Advocacy or Extortion? It Still Depends on the Court,” The Recorder (May 10, 2023)
  • “Does Remote Testimony Eliminate the 100-Mile Rule?,” Law.com (October 13, 2022) (with Tim Heafner and Talia Alsalam)
  • “Advocacy or Extortion? It Depends on the Court,” The Recorder (March 22, 2022) (with Emma Lux)
  • Stars, Paparazzi, and the Puzzling Law of Copyrights,” IPWatchdog (November 22, 2021) (with Megan Smith)
  • “Music Modernization Act Gets New Year Update,” Daily Journal (December 24, 2020) (with Daniel Cooper)
  • "Winner's Playbook: Behind The Scenes Of The Pacquiao Case," Law360 (May 13, 2020)
  • “Caution, Preclusion Ahead: The New TTAB Landscape,” Law360 (September 21, 2018) (with Megan Smith) 
  • “Top Rank’s Victory Helps Firms Protect Exclusivity Provisions,” SportsBusiness Journal (August 24-30, 2009)


  • Honorable Stephen S. Trott, US Court of Appeals, Ninth Circuit


  • US Department of Defense (1998)