Michael McMahon


I take a results-oriented approach to helping clients win commercial disputes and resolve compliance concerns.

Michael McMahon has extensive experience, both at Cooley and as a former Department of Justice (DOJ) trial attorney, leading complex commercial matters and internal investigations. Michael has acted as lead trial counsel on behalf of both plaintiffs and defendants in complex commercial matters involving claims of fraud, trade secret misappropriation, misuse of confidential information, and breach of contract, and in numerous high-stakes post-acquisition disputes in M&A matters on behalf of purchasers, sellers and underwriters. Michael also regularly represents companies and individuals facing investigations from federal and state government entities, such as the DOJ, SEC and state AG Offices.

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  • Cooley + Coalition Secure Strengthened Protections for Children in Immigration Custody 

  • Federal Judge Upholds Equitable Admissions Policy for Boston Exam Schools 


  • Boston College Law School
    JD, magna cum laude, 2010

  • Boston College
    BA, International Studies
    cum laude, 2004

Admissions & Credentials


Rankings & Accolades

    Best Lawyers: Ones to Watch in Commercial Litigation and Criminal Defense-White Collar