Mr. John Duncan, age 74, of Fayetteville, Georgia, passed away on April 5, 2026, at his home surrounded by family. John was born in Los Angeles and grew up in sunny Southern California, son of the late John Duncan and Theresa Guillory Thrift, alongside his brother Bradley Duncan. He was a high school graduate of Sylmar High in 1971, and worked as a computer programmer for several companies from 1980 to 2013. It was at work that he met his wife of 42 years, Karin (Simonsen) Duncan. The couple married in San Dimas, California, before making several moves, first to Kent, Washington in November of 1983; then to Elgin, Illinois, in May of 1992; then to Peachtree City, Georgia, in May of 1998, before finally settling in Fayetteville.

John’s hobbies included sailing in his early years, and riding motorcycles. His love of motorcycles led him to become a member of the Gold Wing Road Riders Association, a group centered around Honda’s Gold Wing model bike, from the years of 2006 to 2015. He was also a Quarter Master for the Boy Scout Troop 181 from the years of 2000 to 2005. 

John’s final years were unfortunately marred by dementia. Much of his time was spent with family at their home, resting after a long life well lived. He is remembered for his sense of humor and willingness to help others, as well as his passion for being a father. He was, and is, dearly loved and missed by his family. 

Along with his parents, John is preceded in death by his brother, Bradley Duncan. 

He is survived by his sister, Stephanie Broderson; his wife, Karin (Simonsen) Duncan; his children Kevin Duncan and Stephanie (Duncan) Boggs, and his son-in-law Evan Boggs; as well as his granddaughter, Kylie Jade Duncan.

A service celebrating John’s life will be held at New Providence Church in Fayetteville, Georgia on April, 26 at 3 p.m.

In lieu of flowers, donations can be made to Providence Preschool at New Providence Church in Fayetteville, Georgia.