Rio S. Pierce

A magna cum laude graduate of Harvard Law School, Rio focuses his practice on ensuring fair and free markets for the benefit of consumers.   


Current Role

  • Associate, Hagens Berman Sobol Shapiro LLP

Recent Success

  • Achieved favorable settlements for group of 80 tenants in tort suit against landlords for slum housing conditions.


  • Prior to joining Hagens Berman, Mr. Pierce worked as an associate for two years at Munger, Tolles & Olson, where he gained significant experience in class action and complex commercial litigation. Mr. Pierce also did extensive pro bono work on immigration matters.  
  • Law Clerk, U.S. Court of Appeals for the Ninth Circuit, Judge Jerome Farris, 2013 – 2014
  • Associate, Munger Tolles & Olson, 2014 - 2016, Mr. Pierce worked extensively on antitrust litigation in the pharmaceutical industry. Mr. Pierce also worked on a mass tort action arising from the accident at the Fukushima Nuclear Power Plant, including participating in briefing before the Ninth Circuit.


  • Serves on the executive committee of the Antitrust Section of the Bar Association of San Francisco

Legal Activities

  • American Association for Justice


  • Chayes Fellow, National Prosecuting Authority in Cape Town, South Africa
  • Teaching Fellow, Copyright EdX


  • “A Heavy Hand or A Light Touch: What Force Will California’s Anti-SLAPP Statute Have After Baral v. Schnitt?” California Litigation Review, 2015

Personal Insight

A proud California native, Rio loves exploring the whole state, especially Big Sur. Prior to law school, Rio worked at Miramax for several years and still loves a good indie film. In his free time, Rio enjoys making pies.