Rear Adm. John Spencer is a native of Fairborn, Ohio, and a 1991 graduate of the U.S. Naval Academy with a degree in Systems Engineering. He earned a Master of Arts in National Security and Strategic Studies from the Naval War College where he was a Halsey Research scholar. He also completed a National Security Fellowship at the Harvard Kennedy School of Government.
His sea tours include division officer aboard USS Maryland (SSBN 738), weapons officer aboard USS Billfish (SSN 676), navigator aboard USS Jefferson City (SSN 759) and executive officer aboard USS San Juan (SSN 751). He commanded USS Philadelphia (SSN 690) in Groton, Connecticut and was commodore of Submarine Squadron 16 in Kings Bay, Georgia.
Staff assignments include instructor duty at the Naval Nuclear Power School, operations officer at Submarine Squadron 11, deputy commander of Submarine Squadron Eight, in the Policy section of the Office of the Secretary of Defense and executive assistant to Commander, U.S. Strategic Command.
His awards include the Defense Superior Service Medal, Legion of Merit, Meritorious Service Medal, Navy-Marine Corps Commendation Medal, Navy-Marine Corps Achievement Medal and various unit and service awards.