John O’Toole focuses his practice on antitrust and competition matters. Mr. O’Toole has experience representing clients in a wide range of antitrust and competition matters, including civil litigation, civil and criminal investigations, counseling, and merger review. Mr. O’Toole has represented clients across multiple fields, with experience in banking, technology, telecommunications, beverage and pharmaceutical industries.

Prior to joining the firm, Mr. O’Toole was an antitrust and competition associate at another multinational law firm in Washington, DC. During law school, Mr. O’Toole served as an intern for the US Securities and Exchange Commission Division of Enforcement.

Professional Memberships

Mr. O’Toole is the Young Lawyer Representative for the American Bar Association Antitrust Section’s Legislation Committee. He is also a member of the National LGBT Bar Association.


  • Experience

    • Represented a wireless telecommunications provider in $26 billion merger, including serving as a member of team that successfully defended merger at trial
    • Represented a number of companies seeking leniency or otherwise being investigated for no-poach investigations


  • Mr. O’Toole was nominated for a 2021 Concurrences Antitrust Writing Award. 

Insights & News


  • Education

    • JD, Harvard Law School, 2017

      Supervising Editor, Harvard Journal on Legislation

      Professional Liaison, Lambda Law

    • BA, Philosophy, Boston College, 2011

      summa cum laude

      Phi Beta Kappa

  • Admissions

    • District of Columbia