Hatch was born on May 21, 1945, in Santa Monica, California, to John Raymond Hatch and Elizabeth Hatch (née White). He grew up with four siblings. While in high school, he aspired to become an athlete in pole vaulting, and only had a passing interest in acting, as he considered himself too shy and insecure. The assassination of President Kennedy in 1963, while Hatch had just started college, turned him towards acting; he had been enrolled in a required oral interpretation course at the time, and following the assassination, presented an article written about Kennedy upon which he said: "As I began to read this article, I got so affected by what I was saying that I forgot myself. I was expressing feelings and emotions I tended to keep locked inside of myself."