The World Junior Memory Championships (WJMC) runs as a subset of the World Memory Championships (WMC).
All competitors need to be between 13 and 17 years old to qualify.
[1] For many countries, in addition to age requirements, one needs to go through a series of regional and national qualification competitions before they can apply for WJMC.
[2] The recent champions are from Mongolia, China and Germany.
[3]