In sporting terminology, a youth system (or youth academy) is a youth investment program within a particular team or league, which develops and nurtures young talent in farm teams, with the vision of using them in the first team if they show enough potential. In contrast to most professional sports in the United States where the high school and collegiate system is responsible for developing young sports people, most football and basketball clubs, especially in Europe and Latin America, take responsibility for developing their own players of the future.

A subset of youth academies are referred to as elite academies, designated for teenagers and young adults. These academies typically have a higher cost of capital incurred for maintaining an optimal environment for practice as well as cups and other competitions that may be partaken.

Elite academies often have full time staff including but not limited to coaches, physiotherapists, office staff and other roles that assist in the operations of the academy. Rules of top academies are strict and unlike other association football clubs, most clubs will have strict travel rules and will not allow players to drive to and from matches on the same day if under the age of 21 due to fatigue levels and stress.

Underage players may sign youth contracts with the club or association that owns the elite academy. It is also common for elite academies to offer the ability to study in parallel with the academy training, such as is the case in for example the system of college sports in the United States. Schools may offer sports focused programmes in order to integrate their student experiences with the academies of affiliation.

Youth systems attached exclusively to one club are often called youth academies. In a youth academy, a club will sign multiple players at a very young age and teach them football skills required to play at that club's level and style of football. Clubs are often restricted to recruiting locally based youngsters, but some larger clubs such as Arsenal, Real Madrid, Manchester United, and Chelsea have recruited foreign talent, leading to the formation of specialist recruiters such as the La Liga Youth Brokerage, which started in 2016.

Many of the larger football clubs in Europe such as Ajax and Feyenoord in the Netherlands, FC Barcelona, Atlético Madrid, and Real Madrid in Spain, Benfica, Sporting CP, and Porto in Portugal, Olympique Lyonnais and Paris Saint-Germain in France, Manchester United, Liverpool, Arsenal, and Chelsea in England, FC Bayern Munich, Borussia Dortmund, and Schalke 04 in Germany, among many others, are regarded as having some of the finest youth academies and have produced many players regarded as some of the best in world football. Other clubs, such as the Brazilian teams Grêmio and São Paulo, Espanyol in Spain, Atalanta, Inter Milan, and AC Milan of Italy, and English clubs Leeds United, Middlesbrough, Watford, Aston Villa, and West Ham United, while not as financially successful as others, have a world class academy. West Ham's youth academy is known as The Academy of Football, and has produced many English talents that have gone on to play with larger clubs in the Premier League.

Another example is lower league clubs who have produced high quality players through the academy and sold them to keep the club running. A prime example of this is Crewe Alexandra who have, under Dario Gradi and his staff, nurtured players into high quality players such as Danny Murphy and Dean Ashton and sold them.

An alternative name for a youth academy is "Centre of Excellence". In English football, these terms have distinct meanings and are licensed and regulated by The Football Association and The Football League.