Barry John (born 6 January 1945 in Cefneithin, Wales) is a Welsh rugby union footballer, considered by many to be the greatest fly-half in the sport's history. In a relatively short career, he took the fly-half game to a new peak and in the process became known simply as "the King".
John arrived at international level in circumstances that would have crippled a lesser player with nerves. He replaced the mercurial David Watkins in 1967, who went north to rugby league when still a student at Trinity College, Carmarthen.