George Franklin Knowlton was born in Farmington, Utah on July 28, 1901. In 1921 he moved to Logan to attend the Utah Agricultural College. In 1923 he received a Bachelor's degree in Entomology. In 1924, soon after receiving a Master's Degree, Knowlton became the Assistant Entomologist at the Agricultural College. He did one year of graduate study at the University of Minnesota then transfered to Ohio State University where in 1932 he received a Ph.D. From 1925 until he became an Emeritus Professor in 1967, Knowlton taught Entomology and Zoology at Utah Agricultural College becoming an associate entomologist in 1930, a research associate in 1939, and a full professor in 1943. After receiving emeritus status, Knowlton continued to serve as a senior consultant on numerous federal grants.

Knowlton's work as entomologist was well known. He published hundreds of articles and pamphlets on various tomato, potato, beet, and berry insects. This research led to studies in the relationship of lizards and birds to insect control methods on farm and rangeland. During World War II, Knowlton served as the U.S. Army Engineers 9th service command entomologist, where he headed and organized the insect and rodent control unit. Later, he provided information on insect control for the U.S. War Department Technical Manual. In addition, he served as Chairman of the Pacific Slope Branch of the American Association of Economic Entomologists, 1940-1941, Vice Chairman of the Rocky Mountain Conference of Entomologists, 1939, and Chairman of the Northwest Vegetable Insect Control Conference 1948-1949.

Knowlton married Mary Brown Watkins in 1925 in the Logan LDS Temple. They had two daughters: Jean (Collmar) and Kathryn (Cazier). Knowlton died on April 8, 1987 at the Logan Regional Hospital.