The 2008–09 I liga was the 61st season of the second tier domestic division in the Polish football league system since its establishment in 1949 and the 1st season of the Polish I liga under its current title (new name).

The league was operated by the Polish Football Association (PZPN).

The league was contested by 18 teams who competing for promotion to the 2009–10 Ekstraklasa.

At the other end, the bottom four teams face automatic demotion to the II liga, while the fate of the 13th and 14th-place finishers will be decided by playoffs.

After the 19th matchday the league will be on winter break between 16 November 2008 and 13 March 2009.