Allyson Slater represents individuals and companies in high-stakes complex civil litigation matters in both state and federal court, as well as in connection with enforcement matters brought by the Securities Exchange Commission and Department of Justice.

Ms. Slater represents clients complex civil litigation matters, including securities class actions, trademark disputes, trade secret actions, civil antitrust matters, and contract disputes. She represents a wide range of clients, including technology companies and biopharmaceutical companies, and has extensive experience handling and managing fast-moving and complex litigation cases on behalf of those clients.  In addition, Ms. Slater conducts high-stakes investigations for corporate clients. Ms. Slater's investigations experience includes internal investigations, as well as investigations under the securities laws, the Bank Secrecy Act and Anti-Money Laundering statutes, and the Foreign Corrupt Practices Act.

Ms. Slater also maintains an active pro bono practice. She has partnered with or represented Planned Parenthood Federation of America and the ACLU Reproductive Freedom Project in numerous cases in state and federal court.  She also currently represents a class of plaintiffs in litigation against the Department of Homeland Security regarding implementation of the provisional waiver statute.

Ms. Slater is a member of WilmerHale's Pro Bono and Public Service Committee.


  • Litigation

    • Successfully defended biopharmaceutical company in securities class action in the District of Massachusetts and subsequent appeal to the First Circuit Court of Appeals
    • Representing boutique guitar manufacturer in trademark and antitrust dispute with a major guitar retailer
    • Currently representing two former yield companies in Sarbanes-Oxley whistleblower litigation initiated by former CEO
    • Successfully obtained temporary restraining order in California state court on behalf of technology company seeking access to its source code and service for its customers
    • Represented technology company in contract dispute over enforcement of terms of service in California state court.
    • Defended major American brewery in trademark dispute brought by a California-based brewery in the Southern District of California
    • Successfully defended major movie exhibitor in federal and state actions where other exhibitors alleged unlawful clearance agreements and purported circuit dealing in violation of the Sherman Act and state laws
    • Represented pharmaceutical manufacturer in qui tam litigation in California state court concerning alleged fraudulent claims submitted to insurers 
  • Investigations

    • Represented utility company in criminal investigation brought by US Department of Justice, parallel civil investigation brought by Massachusetts Attorney General, and inquiry by Massachusetts Department of Public Utilities
    • Represented university in response to investigation request from the National Institutes of Health regarding researchers’ undisclosed foreign affiliations
    • Conducted an investigation of whistleblower allegations concerning a company’s security and competitive intelligence practices on behalf of a special committee of a technology company
    • Represented a former BSA/AML officer in an investigation by the DOJ
    • Represented audit committee of board of directors of networking technology company in SEC and DOJ inquiries into business practices in Russia and allegations implicating anti-bribery, internal controls, and books and records provisions of the Foreign Corrupt Practices Act


  • Selected by peers for inclusion Best Lawyers: Ones to Watch for commercial litigation (2023–2024) and securities litigation (2024).
  • Named to Boston Magazine’s Top Lawyers list in 2023 in the area of commercial litigation. 

Insights & News


  • Education

    • JD, University of Southern California Law School, 2012

      Senior Note Editor, Southern California Law Review, Public Interest Law Foundation Grant Recipient
    • BA, History, Boston College, 2006

  • Admissions

    • Massachusetts

    • California



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