The 2012–13 I liga was the 65th season of the second tier domestic division in the Polish football league system since its establishment in 1949 and the 5th season of the Polish I liga under its current title.

According to the competition rules, all clubs are required to field at least one youth player (born on 1992 or later and trained in Poland) in every game (except for the times when the only youth player on the roster is sent off or unable to continue playing, in which case he can't be substituted by a senior player).

[3] On 28 February 2013 the Disciplinary Commission of the Polish FA suspended the ŁKS's license to compete in the I liga, because of non-payment of salaries to former players.

[4] Since the club's appeal was unsuccessful, on 5 April the Polish FA announced the cancellation of Warta–ŁKS game on the 22nd match day.

[7] The club also withdrew its reserve team from Bytom region Klasa A (7th level).