William Summers Jr. was a Machinist Mate Second Class and Petty Officer in the United States Navy who disappeared while in port at the Naval Shipyard in Bremerton, Washington on January 4, 1982. His ship, the U.S.S. Robison (DDG-12), was in port at the time of his disappearance, and he has not been seen since.

Originally from Alabama, Summers had become intensely religious around the time of his disappearance and had been raised in the Baptist faith. Although he was known to be quiet and reserved, he sometimes got into arguments about religious issues, and some of these altercations became physical. It has been theorized that he may have joined a cult.

Before his disappearance, Summers had expressed a desire to move to Canada. He enjoyed fishing, playing tennis, and working with handicapped children. Despite extensive investigations, his case remains unsolved, and he has not had any contact with his family since his disappearance.