William E. Hall was born in Storrs, Utah. After graduating from the Wasatch Academy and the University of Redlands in California, he enlisted in the U.S. Navy from Utah in May 1938. He received his golden wings as a naval aviator and a commission as an ensign in the U.S. Naval Reserves in September 1939 and was assigned to Scouting Squadron 5 (VS-5) aboard the USS Yorktown. In February 1942, soon after the attack on Pearl Harbor, he participated in raids on Japanese bases in the Marshall and Gilbert Islands. In April 1942, he transferred to Scouting Squadron 2 (VS-2) aboard USS Lexington.
By May 7 and 8, 1942, then Lieutenant (Junior Grade) Hall's squadron, flying SBD Dauntless dive bombers, was heavily involved in the Battle of the Coral Sea. His skill as a dive bomber pilot helped with the destruction of the Japanese aircraft carrier Shoho on May 7. On May 8, as American and Japanese carriers exchanged attacks, he aggressively engaged superior numbers of enemy planes, resulting in his shooting down of three enemy aircraft, one torpedo bomber and two escorting fighters. Despite serious wounds to his feet and head, he brought his scout bomber and his aerial gunner safely back aboard the USS Lexington. For his "extreme courage and conspicuous heroism" on these occasions, LT (j.g.) Hall was awarded the Medal of Honor.
After spending the rest of 1942 in the U.S. Naval Hospital in San Diego, LT Hall married his charge nurse, Leah Christine Chapman, in Price, Utah in September 1942 and became a flight instructor at U.S. Naval Air Station Pensacola, Florida. He remained in training and staff duties until the end of the war, when he was released from active duty, and retired from the U.S. Naval Reserve as a Lieutenant Commander in November 1960 after 22 years of service.