The 2013 IRB Junior World Championship was the sixth, IRB Junior World Championship, an annual international rugby union competition for Under 20 national teams.

England were crowned the 2013 champions for the first time after defeating Wales 23–15 in the final on the 23 June at Stade de la Rabine in Vannes.

After finishing first at the 2012 IRB Junior World Rugby Trophy, the United States were promoted to this competition for 2013.

[1] Their stay in the IRB Junior World Championship was short-lived, however, as they lost in the 11th-place final to Fiji 46–12 and were relegated to the IRB Junior World Trophy, being replaced for the 2014 competition by its winners Italy.

[2] For the first time since the competitions inception, the final was contested by two northern hemisphere teams.