The 2012 IRB Junior World Championship was the fifth IRB Junior World Championship, an annual international rugby union competition for Under-20 national teams. This competition replaced the now defunct Under 19 and Under 21 world championships. The event was held in South Africa between 4 and 22 June 2012 and organised by world rugby's governing body, the International Rugby Board (IRB). A total of 12 nations played in the tournament. New Zealand came into the tournament as defending champions. South Africa were crowned 2012 champions after defeating New Zealand 22–16 in the final on 22 June at Newlands Stadium.