U20

U20, short for under-20, is a designation used in sports and other fields to describe participants who are twenty years old or younger. It is commonly applied to age-restricted competitions and development squads, allowing younger athletes to compete against similarly aged peers and to transition to senior levels.

In association football (soccer), U20 denotes youth national teams and tournaments for players aged 20 and under. The most widely known are the FIFA U-20 World Cup for men and the FIFA U-20 Women's World Cup, which bring together national teams from around the world on a biennial cycle. Eligibility rules are defined by the organizing bodies and typically require players to be born on or after a cutoff date that ensures they are 20 or younger at the start of the calendar year of the tournament; some editions may permit a limited number of older players.

In ice hockey, the IIHF World Junior Championship, commonly referred to as the World Juniors, is the premier under-20 international tournament and a showcase for young players, held annually with teams from member nations.

In rugby union, the World Rugby Under-20 Championship and the World Rugby Under-20 Trophy are global competitions for national teams with players under the age of 20, serving as pathways to senior international rugby.

Other sports also use U20 categories, including basketball and other disciplines, with various national and international federations organizing under-20 championships and development leagues to nurture young talent.

Notes: the label can appear as U20 or U-20, and exact age cutoffs vary by competition; the term is primarily used to describe age-group programs in sports, though it may appear in other contexts as well.