Mark Joseph O'Neil, beloved father, grandfather, brother, uncle and friend, passed away peacefully surrounded by family on June 13, 2025, in Burlington, MA. Born on December 12, 1952, in Melrose, MA, Mark lived a life marked by dedication, kindness, and a deep commitment to those he loved.

Mark graduated from Charles River Academy and began his career working alongside his brother John at their father's company, John F. O'Neil Incorporated. He later attended the Hobart Institute of Welding Technology, where he earned his Welding Certification. A proud member of Pipefitters Local 537, Mark spent many years working, mentoring, teaching, and forging lasting friendships within the trade.

Known for being soft-spoken yet deliberate with his words, Mark cared deeply for others and showed it by being a constant presence at family dinners, cookouts, sporting events, holidays, birthdays, and life's milestones. He cherished telling stories and reminiscing about the rich experiences of his life. His getaways to Vermont with friends were among his most cherished traditions. Mark was loved and respected by everyone who knew him, leaving a lasting impact on his community through his warmth and generosity.

Mark is survived by his daughter, Meaghan J. Corning, and her husband, Kenneth, of Salem; his son, Mark J. O'Neil, and his wife, Kristen, as well as his cherished grandchildren Jack and Tucker, of Beverly; his sisters, Mary O. Angelos and her husband, Nicholas, of Andover, and Barbara G. Thompson of Melrose; as well as many nieces, nephews, and other loved ones. He was predeceased by his parents, John F. O'Neil and Mary E. (Maher) O'Neil and his siblings, Kathleen A. O'Neil and John G. O'Neil.

Visitation will be held on Thursday, June 19, 2025, from 4:00 PM to 7:00 PM at Gately Funeral Home, 79 W. Foster Street, Melrose. A Funeral Mass will be celebrated on Friday, June 20, 2025 at 10:00 AM, at Saint Mary's Church, Herbert Street, Melrose, followed by burial at Saint Patrick Cemetery, Stoneham, MA. Family and friends are respectfully invited to attend.

In lieu of flowers, donations may be made in Mark's memory to the American Cancer Society.