The 2018 AFC Champions League will be the 37th edition of Asia's premier club football tournament organized by the Asian Football Confederation (AFC), and the 16th under the current AFC Champions League title.
The winners of the 2018 AFC Champions League will qualify as the AFC representative at the 2018 FIFA Club World Cup in the United Arab Emirates. If a team from the United Arab Emirates wins the AFC Champions League, the runners-up will also qualify (in place of the winners of the 2017–18 UAE Pro-League).
The AFC Competitions Committee proposed a revamp of the AFC club competitions on 25 January 2014, which was ratified by the AFC Executive Committee on 16 April 2014. The 46 AFC member associations (excluding the associate member Northern Mariana Islands) are ranked based on their national team's and clubs' performance over the last four years in AFC competitions, with the allocation of slots for the 2017 and 2018 editions of the AFC club competitions determined by the 2016 AFC rankings:
The associations are split into two regions:
West Region consists of the associations from the West Asian Football Federation (WAFF), the Central Asian Football Association (CAFA), and the South Asian Football Federation (SAFF).
East Region consists of the associations from the ASEAN Football Federation (AFF) and the East Asian Football Federation (EAFF).
In each region, there are four groups in the group stage, including a total of 12 direct slots, with the 4 remaining slots filled through play-offs.
The top 12 associations in each region as per the AFC rankings are eligible to enter the AFC Champions League, as long as they fulfill the AFC Champions League criteria.
The top six associations in each region get at least one direct slot in the group stage, while the remaining associations get only play-off slots:
The associations ranked 1st and 2nd each gets three direct slots and one play-off slot (in play-off round).
The associations ranked 3rd gets two direct slots and two play-off slots (both in play-off round).
The associations ranked 4th gets two direct slots and two play-off slots (both in preliminary round 2).
The associations ranked 5th gets one direct slot and two play-off slots (both in preliminary round 2).
The associations ranked 6th gets one direct slot and one play-off slot (in preliminary round 2).
The associations ranked 7th to 12th each gets one play-off slot (in preliminary round 1).
The maximum number of slots for each association is one-third of the total number of clubs in the top division (e.g., Australia can only get a maximum of three total slots as there are only nine Australia-based clubs in the A-League).
If any association gives up its direct slots, they are redistributed to the highest eligible association, with each association limited to a maximum of three direct slots.
If any association gives up its play-off slots, they are annulled and not redistributed to any other association.
The final association ranking used to determine the slot allocation was published on 30 November 2016.
Notes
In the following table, the number of appearances and last appearance count only those since the 2002–03 season (including qualifying rounds), when the competition was rebranded as the AFC Champions League.
The schedule of the competition is as follows.
