Hugh Michael O’Brien IV

31 July 1969 · 3 August 2026

Hugh Michael O’Brien IV (“Mike”), 57, of San Diego, California, passed away on August 3, 2026, at UC San Diego Jacobs Medical Center, surrounded by his family, after a three-and-a-half-year fight with stage 4 pancreatic cancer.

Mike was born on July 31, 1969, in Subic Bay, Philippines, to Hugh Michael O’Brien III and Julie Apello O’Brien. After graduating from George Dewey High School, he attended San Diego State University and received a Bachelor of Science in Computer Science. He spent thirty years as a software engineer, most of them with defense contractors, including more than twenty years at L3Harris.

He met Maribelle in college in 1989. They married in 1993 and received the sacrament of holy matrimony in the Catholic Church in 1998. They built their family and home in San Diego and worshipped at St. Anne Catholic Church, where Mike loved the Traditional Latin Mass. He was a devoted husband, father, and brother. He loved figuring out how things worked and making them better, and he loved the outdoors, camping, and the open road. A man of deep faith, he met his illness with grace, humor, and courage.

He is survived by his wife, Maribelle B. O’Brien, and their children, Mikey, Marisa, and Maria.

He is also survived by his father, Hugh Michael O’Brien III; his mother, Julie Apello O’Brien; his stepmother, Nora O’Brien; and his siblings, Tara, Tim, Sammi Jo, and Kimberly.

Services

Memorials

In lieu of flowers, donations may be made to the Pancreatic Cancer Action Network (PanCAN), in his memory.

Condolences may be shared at dignitymemorial.com/obituaries/12994587.