Michael A. Lesser

A dedicated attorney at Thornton Law Firm LLP in Boston, Massachusetts, Michael A. Lesser heads the firm’s Whistleblower Section. After first clerking with the firm, he came aboard as an associate in 1995 and has since built a practice representing people who bring securities law misconduct to light under the SEC Whistleblower Statute, as well as individuals who report fraud under federal and state False Claims Act laws. His work spans civil litigation, class actions and tort matters.

Over the years at Thornton Law Firm LLP, Mr. Lesser has also stood up for clients in a wide range of cases, including claims involving asbestos exposure, glycol ether toxicity and lead poisoning. From 1996 to 1999, he served as a special assistant attorney general for the Commonwealth of Massachusetts, playing a key role on the trial team in the state’s landmark litigation against the tobacco industry.

Mr. Lesser graduated cum laude from Brandeis University in 1992 and earned his J.D. from Boston University School of Law in 1995. He was admitted to the Massachusetts Bar Association in 1995 and is also admitted to practice in the U.S. District Court for the District of Massachusetts (1997) and the U.S. Court of Appeals for the 1st Circuit (2006).

Among his notable accomplishments, Mr. Lesser helped secure a record-setting SEC whistleblower award in 2020 for an FX trader at Bank of New York Mellon – then the largest individual award in SEC history – based on original information that contributed to a successful enforcement action and returned significant funds to investors.

Mr. Lesser has been named by ALM Media as one of New England’s Top Rated Lawyers, was recognized as an “Up and Coming Lawyer” by Massachusetts Lawyers Weekly in 2002 and has received Distinguished* peer-review ratings through Martindale-Hubbell. He is also an active member of the American Bar Association, the American Association for Justice and the Taxpayers Against Fraud.

*AV®, AV Preeminent®, Martindale-Hubbell Distinguished and Martindale-Hubbell Notable are certification marks used under license in accordance with the Martindale-Hubbell certification procedures, standards and policies. Martindale-Hubbell® is the facilitator of a peer-review rating process. Ratings reflect the anonymous opinions of members of the bar and the judiciary. Martindale-Hubbell® Peer Review Ratings™ fall into two categories – legal ability and general ethical standards.