Thomas Patrick Lydon

Thomas Patrick Lydon passed away peacefully on the morning of January 6, 2026. Born in Philadelphia, Pennsylvania, on March 18, 1932, he was the son of Irish immigrants who came to the U.S. in the 1920s. Growing up during the Depression wasn't easy, and it taught Tom early on that you have to work for what you get, a mindset he carried for the rest of his life.

At age 17, Tom enlisted in the Navy. He served during the Korean War as an Engineman 2nd Class (EN2) aboard the USS LSIL-1091. He had plenty of stories from his time at sea, but the one he told most often was about a mission in Wonsan Harbor. While transporting intelligence officers, they realized at sunrise that they had drifted right past a floating mine. The crew tried to shoot it to detonate it but missed. Tom always said it was lucky they missed, or the ship might have gone up with it.

After his honorable discharge in 1953, Tom came home and got to work. He earned his Bachelor's Degree from Drexel University by attending night classes while working full-time during the day.
Tom spent his career in the early days of the computer industry, long before it was what it is today. He started at Univac, working on first-generation machines alongside Grace Hopper, the creator of COBOL. Later, at Computer Control Corporation (3C), he sold systems to NASA for the Apollo Launch program. He was always proud to see equipment he sold standing at the Kennedy Space Center years later.

His work in technology took the family all over the country, from managing sales at Honeywell to building the team at Prime Computer. The job moved the Lydons from Philadelphia to Massachusetts, down to Florida, over to Los Angeles, and finally to San Diego in 1984 with Celerity Computing.
But the most important part of his journey actually happened right back at the start, in San Diego. Just after leaving the Navy, he met Dorothy Rose Haggerty. She was also from Philadelphia but happened to be in San Diego on a summer trip. It was a funny coincidence that two kids from the same city had to travel 3,000 miles to find each other.
Together, Tom and Dorothy built a full life. They raised six children, and Tom taught them by example: show up, do the right thing, and keep your word. He was a man of deep faith and a longtime parishioner at San Rafael Parish in Rancho Bernardo.

We are going to miss him, but we find comfort knowing he is back with Dorothy, who passed away in 2006, and his infant daughter, Denise. After twenty years apart, they are together again.

Thomas is preceded in death by his wife, Dorothy Rose Lydon; his daughter, Denise; and his parents. He is survived by; his sister, Peggy, six loving children: Tom, Terry, Mark, Neil, Michele, and Michael; his 16 grandchildren; and his 6 great-grandchildren.

Mass of Christian Burial:
Thursday, January 29, 2026, at 10:00 AM
San Rafael Catholic Church
17252 Bernardo Center Drive, San Diego, CA 92128
A reception will follow from 11:00 AM to 1:00 PM in the Parish Hall.

Interment & Military Honors:
to be scheduled
Fort Rosecrans National Cemetery, Point Loma
Thomas will be laid to rest with military honors, joining his wife Dorothy in Columbarium CB1.