He was born March 9, 1929, to Morris Edward Gay and Sarah Eleanor (Kerr) Gay, in McKinney, Texas. John graduated from the original McKinney Boyd High School in 1947. He attended Southern Methodist University (SMU), completing his undergraduate studies in 1951, and later earned his law degree from SMU in 1954.

John practiced law in Collin County for more than 60 years, including over 50 years as general counsel of the North Texas Municipal Water District. Millions can thank him for helping to create clean drinking water in North Texas.

John married Judy Leatherman in Fort Worth in October 1959. They raised three beautiful children in their 61 years of marriage: Jennifer, John and David.

John held leadership positions in many public service organizations, including McKinney Rotary Club as President in 1959, and later he became a Paul Harris Fellow. He also served on the boards of The Children’s Advocacy Center of Collin County, Heard Natural Science Museum, McKinney Chamber of Commerce, McKinney Education Foundation, and First United Methodist Church of McKinney.

In 1985, John was elected to the McKinney City Council and served until 1991.  He was elected and served as Mayor of McKinney until 1997, a period of great economic expansion.

The McKinney Chamber of Commerce named him Citizen of the Year in 1999. In 2009, the City of McKinney named its newest library after John & Judy Gay.

John is preceded in death by his parents, Morris and Eleanor Gay. He is survived by his wife, Judy Gay, of McKinney; daughter, Jennifer Sproull, and husband Bill, of Richardson; sons, John Mark Gay, and partner Hajni, of Denver, CO, and David Gay, and wife Arlene, of San Antonio; grandson, Alan Simants, and partner Erin, of Dallas; granddaughter, Taylor Smith, and partner Blake, of Reno, NV; twin grandson and granddaughter, Ryan and Maggie Sproull of Richardson; niece, Judy Moody, and husband Jim, of Celina; nephew, Jim Coleman, and wife Cindy, of Katy; cousin Betty Skelton, and husband Jim, of Houston; cousin, Shannon Boggan, and husband David, of College Station; cousin, Blake Boyd of Los Angeles, CA; and numerous great-nieces, nephews, cousins, and other relatives.