Mark Merlini is a Partner with Marks, O’Neill, O’Brien, Doherty & Kelly. He is admitted to practice in Pennsylvania as well as the Eastern, Middle and Western United States District Courts of Pennsylvania. 

Mark graduated from Boston College in 2001, with a Bachelor of Arts in English and Communications. He attended Temple University Law School, graduating in 2005. During law school, he focused on Temple’s Trial Advocacy Program and participated in clinical programs through the Philadelphia District Attorney’s Office and the Camden Public Defender’s Office. Also, during law school, Mark was a clerk for the Honorable Albert W. Sheppard in the Philadelphia Commerce Court Program. There, he learned from a legendary judge and great mentor.

Following law school, Mark worked for a medical malpractice defense firm gaining great courtroom experience and representing physicians and healthcare providers at every stage of litigation, including participation in multiple trials in Philadelphia and the surrounding counties and arguments before the Pennsylvania Superior and Commonwealth Courts.

Since joining Marks O’Neill in 2012, Mark has continued representing physicians and other healthcare providers, including nurses, physicians’ assistants, nurse practitioners, hospitals, health systems, long term care facilities, home care providers and behavioral health facilities in malpractice actions. In addition, he has handled several cases involving civil rights claims in federal courts including prisoner civil rights/malpractice claims against physicians and other healthcare providers treating the prison population.  He also gained experience representing a variety of clients in general liability and product liability matters and has tried several cases to verdict.

Mark has been included on the Super Lawyers Rising Star list for Pennsylvania from 2014-2017. He has presented lectures to lawyers, law students and insurance executives relating to subjects including prisoner malpractice litigation, the impact of the 2003 MCARE Act in Pennsylvania and issues in the litigation of cases against physicians’ assistants.

He enjoys spending time with his wife, Suzanne, and three children and coaching in the Oreland-Wyndmoor Little League. He is still a hopeful Philadelphia sports fan with trust in the process.

Mark P. Merlini, Jr.

Phone 215-832-4228

Mark P. Merlini, Jr. PDF


  • J.D., Temple University, 2005
  • B.A., Boston College, 2001

Bar Admissions

  • Pennsylvania
  • U.S. District Court for the Eastern District of Pennsylvania
  • U.S. District Court for the Middle District of Pennsylvania
  • U.S. District Court for the Western District of Pennsylvania

Bar Associations

  • Pennsylvania Bar Association

Practice Areas

  • Casualty Group
  • Healthcare & Catastrophic & Excess Loss
  • Professional Liability

Representative Cases