The league is split into western and an eastern division.

The league started in 1989-1990 and was named TFF PAF Ligi (Profesyonelliğe Aday Futbolcular) until the 2008–09 season.

From 2009 till 2014 the league was called TFF A2 Ligi.

Teams are not relegated from the U21 Ligi based on their final league position, but on the league position of their respective clubs' senior teams.

Until 2009, only U21 teams of the Süper Lig could participate in the U21 Ligi.