Cornelius J. Sullivan, 86, of Concord, Mass., died Friday, May 22, after a long illness. He was the beloved husband for 64 years of Maureen (Walsh) Sullivan, formerly of Fall River. Born in Fall River, the son of the late Cornelius J. and Mildred Sullivan, Neil graduated from B.M.C. Durfee High School and attended Brown University before volunteering to serve in the U.S. Army during the Korean War. Upon returning to the United States, he went to Northeastern University, from which he graduated with a B.A. degree with honors. Before retirement, Neil worked for Honeywell and later Raytheon as a human resources manager. He lived in Concord for 40 years and then in Tewksbury for 10 before returning to Concord. A member of Holy Family Parish, he was a Eucharistic minister and choir member for many years. He was also a former president of Minute Man Arc. In addition to his wife, Maureen, Neil is survived by his daughters Colleen Sullivan and her husband, Chris Grujon, of Oregon; Cathleen Mandrioli and her husband, Paul, of Concord; Nancy Sullivan-Lord and her husband, Dan Lord, of Rhode Island; and a son, Neil Sullivan, of Taunton. He was predeceased in 2018 by his daughter Cheryl. He leaves four grandchildren: Jill, Michael and Casey Mandrioli, and Rachel Sullivan-Lord. He is predeceased by a sister, Katherine Kilroy, of Tiverton, Rhode Island, and survived by a sister, Judith Reis, also of Tiverton. Due to current restrictions because of COVID-19, immediate family members will gather privately in Dee Funeral Home. Burial will follow at St. Bernard's Parish Cemetery in Concord, where officers of the U.S. Army will recognize Neil's honorable service with military honors. The Town of Concord's flag will fly at half-staff on the day of his burial in recognition of his service to our country. In lieu of flowers, contributions can be made to Neil's favorite nonprofits: Minute Man Arc, 35 Forest Ridge Road, Concord, MA 01742 or Rosie's Place, 889 Harrison Avenue, Boston, MA 02118. Arrangements are under the care of Dee Funeral Home & Cremation Service of Concord.