By his junior year, his father was stationed in Japan, where Hamill attended and was a member of the Drama Club at Nile C. Kinnick High School, from which he graduated in 1969.
Gdy jego ojciec stacjonował w Japonii, Hamill uczęszczał do Yokohama's High School i był członkiem Drama Club przy Nile C. Kinnick High School, którą ukończył w 1969.