 During World War II, following a period observing British commando training in England and Scotland, he returned to the 1st Marine Division and served as executive officer and later commander of the 1st Marine Raiders Battalion on Guadalcanal, and executive officer of the 1st Raider Regiment in operations on New Georgia.He received the Navy Cross on Guadalcanal in September 1942 for "extreme heroism and courageous devotion to duty" during the fighting near the Matanikau River.During this action, Griffith suffered wounds for which he was awarded the Purple Heart.