Attorney Mark O'Connor has been practicing law since 1986 in Medford, Massachusetts. For the past 25 years, he has worked as a sole practioner with concentration in the areas of real estate, personal injury, wills and trusts, civil litigation, business and probate law. He has a second office in Tewksbury, Massachusetts for the convenience of clients in the Merrimack Valley region.

Attorney O'Connor is a member of the Massachusetts Bar Association and the federal bar, District of Massachusetts. He is a recipient of a Pro Bono Award from the Volunteer Lawyers Project.

Outside the office, Mark O'Connor serves as a volunteer with Strongwater Farm, a therapeutic horse riding program. He previously served as a board member and coach with the Tewksbury soccer and basketball leagues, a youth and high school soccer referee, and an elected town library Trustee. 

Attorney O'Connor graduated from Williams College in 1982 and Suffolk University Law School in 1986.