Michael A. Lesser


Settled | Resolved Cases

Mr. Lesser joined Thornton Law Firm as an associate in 1995 after previously clerking at the firm. He heads the firm’s Whistleblower litigation section, with a focus on representing individuals that report violations of securities laws subject to the SEC Whistleblowing statute and individuals that report fraud on the government through the Federal and state False Claims Act statutes.

In 2020 Mr. Lesser's client, an FX trader who worked for Bank of New York Mellon, was awarded the then largest individual SEC whistleblower award in the history of SEC whistleblower litigation. The  client's almost $50 million dollar award was for providing original information to the Securities and Exchange Commission that resulted in a successful enforcement action that returned a significant amount of money to harmed investors.

Mr. Lesser was selected as one of New England's 2020 Top Rated Lawyers by ALM Media and Martindale-Hubbell™. Mr. Lesser was named an Up-and-Coming Lawyer by Massachusetts Lawyers’ Weekly in 2002. He has also been selected as a Massachusetts Super Lawyers Rising Star for 2010.

  • Brandeis University (B.A., cum laude, 1992)
  • Boston University (J.D., 1995)
  • Named an "Up and Coming Lawyer" by Massachusetts Lawyers' Weekly in 2002
  • Named a Super Lawyers "Rising Star" in 2005 and 2010
  • Named a New England's 2020 Top Rated Lawyer by ALM Media and Martindale-Hubbell™
  • Named a Massachusetts Super Lawyer in 2021
  • Member, American Bar Association
  • Member, The American Association for Justice
  • Member, Taxpayers Against Fraud

Then-largest-ever individual SEC whistleblower award - 2020

• Spirito v. Hyster New Eng., Inc., et al., 70 Mass. App. Ct 902, 827 N.E.2d 1160 (2007)


  • 1995, Massachusetts
  • 1997, U.S. District Court, District of Massachusetts
  • 2006, U.S. Court of Appeals, First Circuit
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