Marissa Lalli's practice focuses on intellectual property litigation and complex commercial disputes. She represents clients in high-stakes patent infringement and licensing disputes involving a variety of technologies, including semiconductors, digital imaging, smartphones, VoIP devices, data storage systems, and automobiles, as well as disputes involving pharmaceuticals. Ms. Lalli also represents clients in trade secret, trademark, unfair competition, and antitrust matters in courts throughout the country. Ms. Lalli's practice encompasses all aspects of  litigation, including pre-suit investigations, pleadings, fact and expert discovery, depositions, motion practice, settlement, trial preparation, trial and appeals. Her experience includes litigating in federal district courts and the International Trade Commission.

Ms. Lalli is committed to pro bono representation. She has achieved significant victories on behalf of individuals seeking political asylum in the United States and disabled veterans appealing the denial of certain disability benefits before the US Court of Appeals for Veterans Claims. She was also a member of the litigation team in a federal class action suit challenging the imprisonment of women in Massachusetts who have been civilly committed for drug or alcohol addiction treatment.

In 2019, Ms. Lalli co-taught the Harvard Law School Patent Trial Advocacy course—a full semester simulation course aimed at preparing students to act as trial counsel in patent cases. In 2016, Ms. Lalli served as a Special Assistant District Attorney in Middlesex County, Massachusetts, where she tried more than a dozen criminal cases to judges and juries. Prior to joining WilmerHale, she was a law clerk for the Honorable Patti B. Saris of the United States District Court for the District of Massachusetts.

Professional Activities

Ms. Lalli is admitted to practice before the US Court of Appeals for the First Circuit and the US District Court for the District of Massachusetts.


  • Selected for inclusion in the 2021–2024 editions of Best Lawyers: Ones to Watch for intellectual property litigation. 
  • Named to Boston Magazine’s Top Lawyers list in 2023 in the area of intellectual property rights.

Insights & News


  • Education

    • JD, Georgetown University Law Center, 2011

      cum laude Executive Notes Editor, American Criminal Law Review
    • BA, History, Columbia University, 2008

      cum laude
  • Admissions

    • Massachusetts

    • New York

  • Clerkships

    • The Hon. Patti B. Saris, US District Court for the District of Massachusetts, 2011 - 2011



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