Mark C. O’Connor is an experienced trial attorney representing clients in a wide range of complex business and commercial matters, providing aggressive and cost-effective representation to a broad range of clients from publicly traded corporations to closely held business owners and entrepreneurial individuals.

Mark has represented clients in many areas of commercial law, real estate matters, employment matters, insurance coverage, probate and estate matters, and intellectual property matters. Mark possesses a combination of skills and experience that makes him stand out and he delivers exceptional results.

Awards & Honors

  • Named a “New England Super Lawyer” by Thomson Reuters, 2005-2012
  • Co-Chairperson of Litigation Practice Group of Ally Law (formerly the International Alliance of Law Firms)
Mark C. O'Connor
Rated by Super Lawyers

loading ...

Representative Matters

  • Successfully represented a commercial property owner in construction litigation.
  • Representation of large Massachusetts reverse mortgage lender.
  • Represented private employer involving enforcement of trade secrets and covenants not to compete
  • Successfully represented a Boston Latin School student facing expulsion
  • Represented clients before the Massachusetts Commission Against Discrimination concerning employment discrimination
  • Successfully defended client against claims brought by the Massachusetts Attorney General’s Office alleging discrimination in lending and refinancing practices
  • Performed pro bono work for individuals who are victims of domestic violence


  • Boston College Law School, J.D., 1983
  • College of the Holy Cross, cum laude, 1978

Bar Admissions

  • Massachusetts

Court Admissions

  • First Circuit Court of Appeals
  • U.S. District Court for District of MA
  • U.S. Bankruptcy Court
  • U.S. Tax Court

Outside the Office

  • Mark is an avid reader of biographies and history, and he enjoys traveling, cooking and golfing. Mark is the proud and lucky owner of two affectionate and adorable goldendoodles, named Cash and Penny.