RJ Gordon is the son of Jason Gordon, a professional golfer. He attended Notre Dame High School in Sherman Oaks, California, in his first three years of high school before transferring to West Ranch High School in Stevenson Ranch, California, in his senior year. He lettered twice at Notre Dame and in his one year at West Ranch. His senior year got cut short due to the COVID-19 pandemic, but he had a junior season, helping lead Notre Dame to a Mission League championship and a berth in the 2019 CIF Southern Division 1 Tournament by hitting .