Chelsea's Under-21s, Under-19s (in some seasons) and Under-18s are the later stages of the development process for young players at the club.

The Under-18s, also frequently referred to by the traditional 'youth team' name, is a side consisting of the youngest players to have been given full-time scholarships by the club having reached the end of statutory education, although the Under-18s league team will often feature schoolboys who are progressing well, especially towards the end of a season.

As well as the league campaign, which is regionalised initially before becoming a nationwide elite league in the later months for those qualifying, an Under-18 side also competes in the long-running and prestigious FA Youth Cup. For this knockout competition, players who have performed quickly enough to be pushed ahead of their age group into the Under-21 squad normally return to play the Youth Cup matches.