John K. Carmack was born 10 May 1931, in Winslow Arizona. After high school, John entered Brigham Young University, where he completed two years of study. He accepted a call to serve as a full-time missionary to the West Central States from 1951 to 1953. After an honorable release, he returned to BYU where he earned a BA. A period of time spent in the military followed his graduation from BYU. After completing his military obligation and returning to civilian life, John determined to pursue the study of law. He enrolled in the University of California at Los Angeles where he earned the Juris Doctor Degree. He entered into the private practice of law and became president of his law firm. John met Shirley Fay Allen while she was pursuing a graduate degree in nutrition. They fell in love and married. The couple would rear five children.

In the Church, John accepted numerous calls. Through the years he was a a public communications council chairman, member of the Westwood Second Ward bishopric, member of the stake high council, counselor in stake presidencies for seven years, president of the Los Angeles California Stake, and Regional Representative. Then in 1981, while awaiting investiture as president of the BYU Alumni Association, he was called into full-time Church service as president of the Idaho Boise Mission. He served as a mission president from 1981 through 1984. 

Elder John K. Carmack was ordained a Seventy and sustained as a member of the First Quorum of Seventy, where he stayed until 2001, when he was released named an Emeritus General Authority.