John Martin O'Neill Jr., 79, of Harrisburg passed away Monday, December 21, 2020 at the Hershey Medical Center. He was born in Philadelphia, PA; the son of the late John M. O'Neill and Marion (Freeman) O'Neill, and the brother of late Patricia Kennedy and Janice McDonald. He worked as a Director of Grievances at AFSCME and served in the Army during the Vietnam War. He was preceded in death by his wife of 43 years, Mary Ann (Calpin) O'Neill. He is survived by his 3 children, John M. O'Neill III, Patrick J. O'Neill, and Megan E. O'Neill; daughters-in-law, Holly O'Neill and Laura O'Neill; and grandchildren, Bailey, Connor, Kaelan, and Aidan. In addition, he is survived by his brother-in-law, Jim Calpin, sisters-in-law, Kate Cavanaugh, Mary Van Dorick, Joann Furlong, Betty Kelble and Marina Calpin. A private service for the family will be held at Indiantown Gap National Cemetery on Friday, January 8, 2021. In lieu of flowers, memorial contributions may be made to Compassionate Care Hospice, at www.amedisys.com/about/foundation or call 717-944-4466.