The champions league was expanded to 35 clubs this year, with 5 teams starting from a knockout qualifying stage.

Each team was allowed to field a maximum of four foreign players this season, one of whom had to be from an AFC Member Association country.

[1] † One of the A-League clubs, Wellington Phoenix, is based in New Zealand, an OFC member country, therefore not being eligible to compete in the ACL.

The clubs are ranked according to points and tie breakers are in following order: Winners and runners-up of each group qualified for the next round.

The 2009 AFC Champions League Final was played on 7 November at National Stadium, Tokyo, Japan.