James Thomas O’Neil

James Thomas “Jim” O’Neil, 84, of Aspen Hill, MD, passed away peacefully on May 18, 2026, after a brief illness. Jim was a devoted and loving husband, brother, step father, uncle, veteran, and a cherished friend to many.

Jim is survived by his wife of 38 years, Jackie (Edwards) O’Neil; his brothers Joseph Leo III (Veronica) of Edgewater, MD, and Francis Xavier of Washington, DC; his sister Rosemary Jenkins of Damascus; his cousin Spencer Dean and numerous nieces, nephews, great nieces and nephews, and great great nieces and nephews. In addition to his parents, Joseph Leo Jr. and Marian (Dyer) O’Neil, he was preceded in death by his brother in law Kenneth Jenkins, and nephews Daniel Jenkins and Patrick O’Neil.

Born on September 30, 1941, in Washington, DC and raised in Southeast. Jim grew up with a strong sense of family, faith, and service. He graduated from St. John’s College High School in 1959 and later attended night school at UDC, where he earned his engineering degree.

Jim volunteered for the U.S. Army, proudly serving during the Cuban Missile Crisis, and received an honorable discharge. One of his proudest accomplishments and thing that brought him a lot of joy was Coaching Football for the Catholic Youth Organization (CYO) at St Francis Xavier for ten years. He went on to build a distinguished 35 year career as a Mechanical Engineer in the Office of Research Facilities at the National Institutes of Health (NIH). In addition, he was a dedicated Usher at the Shrine at Saint Jude’s Catholic Church in Rockville, MD.

A lifelong and avid Washington Redskins fan, Jim also loved traveling with Jackie and their close lifelong friends. Known affectionately as “Uncle Boh,” he delighted in attending family gatherings, holidays (known for his homemade fudge and peanut butter candy), and summers in Rehoboth Beach with extended family. He especially enjoyed treating his nieces and nephews to the annual trip to Kings Dominion and souvenirs from his travels— treasured memories for generations.

Jim will be remembered for his joyful spirit and his gift for making people laugh. His warmth, humor, and unwavering positivity touched everyone who knew him.

Visitation and Mass will be held at Our Lady of Mercy Catholic Church in Potomac, MD on Thursday, May 28 a 10am Visitation followed by Mass at 11am with Rev. Raymond O’Brien as celebrant. Burial will follow at Fort Lincoln Cemetery at 130pm.