 | This article relies largely or entirely on a single source. (February 2012) |
 | |
| Tournament details | |
|---|---|
| Host |  South Africa |
| Date | 4–22 June 2012 |
| Teams | 12 |
| Final positions | |
| Champions | South Africa |
| Runner-up |  New Zealand |
| Third place |  Wales |
| Tournament statistics | |
| Matches played | 30 |
← 2011   2013 → | |
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.
After finishing last at the 2011 IRB Junior World Championship, Tonga had been relegated to the IRB Junior World Trophy and therefore did not participate in this year's event. They had been replaced with Samoa, who won the 2011 IRB Junior World Rugby Trophy. Italy were relegated to the IRB Junior World Trophy for 2013 after losing the last place play-off to Fiji. They were replaced in 2013 with the United States, winner of the 2012 IRB Junior World Rugby Trophy.