The FIVB Volleyball Men's U21 World Championship, called the FIVB Volleyball Men's Junior World Championship between 2007 and 2011, is the world championship of volleyball for male players under the age of 21 organized by Fédération Internationale de Volleyball (FIVB).
The first edition was staged in 1977 in Brazil and tournaments have been played every four years for the first three editions and every two years since then. The most recent tournament was hosted by Bahrain in the city of Manama and won by Iran.
Russia is the most successful nation in the tournament's history, with six titles and three runners-up. Brazil is the second most successful with four titles and six runners-up.
A corresponding tournament for female players is the FIVB Volleyball Women's U21 World Championship.
