Dennis Michael O’Neal died Friday, December 19, 2025, at his home in Sacramento, CA, after a gradual decline due to metastatic kidney cancer. He was 80 years old. He was born October 12, 1945, in Bloomington, IL, the son of Everett E. O’Neal and Kathryn E. (Smallwood) O’Neal. His family settled in Washington, IL, in 1946, staying there until 1959, when they moved to Morton. After graduating from Morton High School in 1963, he served in the Air Force, where he became an electronics technician maintaining C-130 and F-4 flight simulators at Davis–Monthan Air Force Base in Tucson, AZ. Following his 1971 discharge, Dennis went on to a career at General Electric in Bloomington, IL, working on large-scale emergency power systems. After a move back to Tucson to escape the Midwest’s harsh winters, he found a new career in data storage and technical writing at IBM in the 1980s. He moved to Sacramento, CA, in 2005, where he rounded out his working life with a stint managing data at the California Cancer Registry.

Dennis always enjoyed a lively chat and a good laugh, and he managed to keep up a friendly and amusing banter with his caregivers until just a few weeks before his death. He maintained a lifelong interest in aviation and had several other significant hobbies. These included music and ballroom dancing, two interests he shared with Jane Sagehorn, his friend and companion in the final years of his life. She also invited him on wide-ranging travel adventures that he enjoyed, especially because they also included visits to his son in Pittsburgh and his daughter and her family in Slovenia. As a talented amateur musician, he sang and played several instruments. He also encouraged his children’s musical ambitions, and as a result music has always been central to both of their lives. He often said that his proudest achievement in life was parenting his two beloved children.

Surviving are his former wife Ilona J. Fecske of Tucson, AZ; children Dawn O’Neal Reindl (Donald) of Ljubljana, Slovenia, and Scott Michael O’Neal of Pittsburgh, PA; grandchildren Erika of Marinette, WI, Klara of Ljubljana, and Kristina of Ljubljana; and great-grandchild Madeline of Marinette. He was preceded in death by his parents and his brothers Terry and Gary.

As per his wishes, there will be no funeral service. In lieu of flowers, donations in his honor to the California Cancer Registry would be welcome.