John Heaphy "Jack" Fellowes (November 22, 1932 – May 3, 2010) was a U.S. Navy captain, pilot, and prisoner of war (POW) during the Vietnam War. He was known as "Happy Jack" because of his infectious sense of humor, which he maintained even while a POW. He was awarded the Silver Star for his "conspicuous gallantry and intrepidity" while a POW, credited with "contributed significantly toward the eventual abandonment of harsh treatment by the North Vietnamese".