GORHAM, MAINE- Mr. John George "Jack" O'Sullivan, Sr., passed away peacefully at his home on April 4, 2025, in Gorham, Maine, at the age of 78. Born on May 1, 1946, in Winchester, Massachusetts, Jack led a full life defined by dedication to his work and devotion to his family and a long list of friends. Over more than fifty years, Jack built a respected career as a parts manager at several automotive dealerships. Known for his unwavering commitment to customer service and excellence in the parts department, he earned numerous awards and the admiration of colleagues and customers alike. His professionalism and reliability left a lasting impression on all who worked with him. Most importantly, Jack found his greatest joy in caring for his grandchildren. Affectionately known as "Papa," he embraced this role wholeheartedly, taking immense pride in their happiness and well-being. His presence was a source of strength and warmth in their lives. In retirement, "Papa" Jack quickly became a staple on the sidelines and in the stands at Gorham youth and High School sporting events; cheering on his grandchildren and their teammates and socializing with everyone he met. Always with a kind word or a witty joke, "Papa" was a fan favorite. His greatest trait was his ability to connect and make everyone he knew feel important and loved. Jack is lovingly remembered by his wife, Cheryl O'Sullivan; his son and daughter-in-law, John and Krista O'Sullivan; grandsons, Cael and Kian O'Sullivan; daughter and favorite son-in-law, Kate (O'Sullivan) and Mike Karlonas; grandson and granddaughter Jack and Emily Karlonas; daughter, Kerri Allen Helmer; granddaughter and grandson, Avery and Brady Allen; brother Dennis O'Sullivan of Salem, New Hampshire and sister in law MaryLynne and husband, Bill Skulski of Palm Coast, FL. He also leaves behind several beloved godchildren, too many nieces and nephews to count, along with their children and grandchildren in Maine and Massachusetts. He will be lovingly missed by his high school friends that he still recently spent quality time with, along with the Gorham community. He was predeceased by his parents, Josephine (Sullivan) O'Sullivan and John F. O'Sullivan; sisters Mary Gardner, Margaret "Peggy" Hutchinson, and Kathleen Gravito; and brothers Richard O'Sullivan, Michael O'Sullivan, and Timothy O'Sullivan. Visitation hours will be held on Monday, April 21, 2025, from 5:00 PM to 7:00 PM at Dolby Blais & Segee Funeral Home, 76 State Street in Gorham. A Funeral Mass followed on Tuesday, April 22 at 10:00 AM at St. Anne's Catholic Church, 299 Main Street in Gorham. In accordance with Jack's wishes, donations may be made to support his grandchildren's sports fundraisers, including his grandson's goal for the 35th Maine Shriners Classic Lobster Bowl football game. https://givebutter.com/MSLBC/team-west/jackkarlonas May his memory bring comfort to all who knew him.