QUINCY, - Denis E O’Brien, 66, of Quincy passed away peacefully on July 22, 2019 surrounded by family. He is survived by his mother Anne O’Brien of Braintree, he and his former wife, Wanda Knopp of Plymouth had 2 children, daughter Krista and her husband Leo McGovern of Avon, and son Kevin O’Brien of Dorchester. He was the loving “PAPA” of Kasey O’Keefe, Leo McGovern, & Madison McGovern. Brother of Dana O’Brien of Duxbury, Stephen O’Brien of Braintree, & Susanne Bonin of Braintree. In addition, he is survived by many nieces & nephews, and many close, long-time friends, Graduate of Braintree High School in 1971 he attended Appalachian State University in Boone, North Carolina. He was a 30 plus year rail road employee and a long-time member of The Carmen’s Union. Denis was an avid golfer, who also enjoyed cooking, dining out, & a good bottle of wine. He enjoyed many trips up North to the mountains. Relatives & friends are respectfully invited to visiting hours on Friday, July 26th, 4 PM-8 PM at Mortimer Peck Funeral Home, 516 Washington St, Braintree. A funeral mass will be held on Saturday July 27th at 10:30 AM at Saint Francis of Assisi Church on Washington St in Braintree, burial will follow in Braintree Cemetery. In lieu of flowers, donations in memory of Denis may be made to The American Cancer Society.