Gardner Edward Sullivan, affectionately known as "Sully" to his many friends, passed away peacefully on Thursday, September 4, 2025, at South Valley Post Acute Rehab Center in Denver, Colorado. He was 78 years old. His passing came after complications from Parkinson's Disease.

Born in Concord, Massachusetts, to Edward Joseph Sullivan and Gwendolyn Prouty Sullivan, Sully dedicated his life to service, family, and community. He served his country honorably in the United States Air Force until his discharge in 1973. During his military service he was stationed in the Philippines, and later in Spain with his young family. After his military service, he built a meaningful career as a computer programmer for Denver Public Schools at Emily Griffith Technical College, where he contributed to the school's technological infrastructure and advancement for many years.

Sully was devoted to his family in his later years and treasured his regular phone calls with his children and grandchildren. He remained an active and engaged member of his community through volunteerism, charitable donations to local foodbanks and non-profits, and participation in his Homeowners Association. In his leisure time, he found joy in the simple pleasures of playing Solitaire, cheering on his beloved Denver Broncos, and immersing himself in mystery novels and films. A lifelong learner, he stayed well-informed as a close follower of both local and national news.

He is survived by his long-time partner, Jean Butler, and his former wife, Mary Sullivan, with whom he raised four children. His loving family includes daughter Tina Son (husband Chris Son, and grandchildren Austin, Ashley, and Aliya) of Virginia; daughter Margi McClung (husband Clinton McClung) of Colorado; and son Richard O'Sullivan (wife Marina, and grandchildren Atlas and Quinn). Sully is also survived by three sisters: Katrina O'Leary of Colorado, Linda Conant of South Carolina, and Wendy Spitale of Pennsylvania. He was preceded in death by his son Edward William Sullivan.

Gardner Edward Sullivan will be remembered for his dedication to family, his service to his country and community, and the warmth he brought to all who knew him as "Sully."

Sully's family and friends will gather for a celebration of life on Monday, November 10, 2025, from 11:30-2:00 pm in the Centerpoint West room at Windsor Gardens, 597 S. Clinton Street, Denver, CO 80247. Please RSVP to Rick Sullivan at rtsulliv@gmail.com if you plan to attend.

In lieu of flowers, please consider making a donation in Sully's honor to the Food Bank of the Rockies or the Parkinson's Association of the Rockies .