George Simmons Hammond was born on May 22, 1921, in Auburn, Maine. Growing up in Auburn his family were charged with the operation of the neighborhood dairy farm on Hardscrapple Road. His father died when Hammond was thirteen. He was the oldest of seven children and was raised by a single mother. From an early age Hammond was charged with running the day-to-day operations of the dairy farm with his mother and older siblings. Hammond's parents were college graduates, but disliked the local schools in Auburn. As a result, he was homeschooled until the sixth grade. Afterwards, he was educated at various Auburn public schools before graduating in 1938. After graduating he took a gap year to continue operating his dairy farm. After his educational hiatus he applied to and was accepted into Bates College, in Lewiston, Maine. He graduated with a Bachelors of Science in chemistry magna cum laude and Phi Beta Kappa in January 1943.