John Clark Keller was born January 15, 1940, in Atlanta, the older son of John G. Keller Jr., and Catherine Louise (McClung) Keller. He attended Terrell public schools, where he excelled in athletics. In 1957–58, his senior year as a Terrell Tiger, he played end, on offense and defense, on a team that won the 2A state high school football championship. He was the leading scorer on the basketball team, which went several rounds in the playoffs. He won state championships in the discus and as a member of the mile relay team. He attended Texas A&M on a basketball scholarship, and graduated with a bachelor’s degree in biology and a master’s in education.

In 1960 he met Annette Smith, of Seagoville, at a wedding of friends they had in common. They started dating soon thereafter, and married on June 3, 1961. He began his career as a football coach and teacher in Dallas. He went on to be the head football coach at high schools in Grand Saline and Castleberry and later coached basketball and football in Arlington. In addition to coaching, he worked for years in the swimming pool business and ran his own company, Regency Pools, in the mid to late 1970s. He later owned several GNC franchises. He ended his career in education as a teacher/coordinator in industrial cooperative education. at Richland High School and at the Shannon Center in the Birdville school district.

An avid sports fan, John cheered on the Dallas Cowboys, the Mavericks, and the Texas Rangers, as well as the Aggies, for decades. He was even more fanatical about his children’s and grandchildren’s athletic pursuits in swimming, football, basketball, baseball, cross country, and track.

John is preceded in death by his parents and sister, Kaye Keller Matsler.

A lifelong Methodist, he was most recently a member of White’s Chapel UMC in Southlake. In addition to Annette, he is survived by his brother Jim Keller (Suzy) of College Station and by his children: John C. (Kip) Keller Jr. (Michael Barnes); Charles Christopher (Kris) Keller (Christy); Claire Keller O’Neal (Matt); Caroline Keller O’Pry (Joel); and by his grandchildren: C. J. Cartwright (Summer); Cameron Keller; Caden Keller (Kelsey); Madeline O’Neal; Kate O’Neal Fowler (Kaj); Connor O’Neal; Colin O’Pry (Destiny); Carissa, Carson, and Cassandra O’Pry; and by his great-grandchildren, Stella and Abby Fowler.

John died in the early hours December 1 from complications due to a broken hip and long-term Alzheimer’s disease. At his request, John’s body was donated to the Willed Body Program at UNT Medical Center. A memorial service was held on Tuesday, January 4, 2022. In lieu of flowers, the family asks that contributions be made to the All Church Home and Family Services, Attention: Development, 3712 Wichita Street, Fort Worth, Texas 76119 or the FWCentral Alzheimers’s Association, 1-800-272-3900.