2023–24 AFC Champions League

The 2023–24 AFC Champions League was the 42nd edition of Asia's premier club football tournament organized by the Asian Football Confederation (AFC), and the 21st and final under the AFC Champions League title, as the competition would be rebranded as the AFC Champions League Elite starting in 2024–25.

This season was the first to have an inter-year schedule from September (autumn-to-spring), instead of an intra-year schedule (spring-to-autumn), since the 2002–03 season. This edition saw an increase in numbers of preliminary players, with 35 players able to be registered; teams were able to field six foreign players in games, where one of these players had to still be from another Asian nation.

The tournament winner qualified for the 2024 FIFA Intercontinental Cup and 2025 FIFA Club World Cup in the United States. Additionally, the winner entered the League stage of the brand-new 2024–25 AFC Champions League Elite if they had not already qualified through their domestic performance.

Urawa Red Diamonds of Japan were the defending champions, but were eliminated in the group stage.

Association team allocation
The 47 AFC member associations were ranked based on their clubs' performance over the last four years in AFC competitions (their national team's FIFA World Rankings no longer considered). The slots were allocated by the following criteria according to the Entry Manual:
 * The associations were split into two regions (Article 3.1):
 * West Region consisted of the 25 associations from the West Asian Football Federation (WAFF), the South Asian Football Federation (SAFF), and the Central Asian Football Association (CAFA).
 * East Region consisted of the 22 associations from the ASEAN Football Federation (AFF) and the East Asian Football Federation (EAFF).
 * The AFC could reallocate one or more associations to another region if necessary for sporting reasons.
 * The top 12 associations in each region could enter the AFC Champions League.
 * In each region, five groups were in the group stage, including 16 direct slots, with the four remaining filled through qualifying play-offs (Article 3.2). The slots in each region were distributed as follows:
 * The associations ranked 1st and 2nd were each allocated three direct slots and one play-off slot.
 * The associations ranked 3rd and 4th were each allocated two direct slots and two play-off slots.
 * The association ranked 5th was allocated one direct slot and two play-off slots.
 * The association ranked 6th was allocated one direct slot and one play-off slot.
 * The associations ranked 7th to 10th were each allocated one direct slot.
 * The associations ranked 11th and 12th were each allocated one play-off slot.
 * The AFC Champions League title holders and AFC Cup title holders were each allocated one play-off slot had they not qualified for the tournament through domestic performance (Article 3.6). The following rules were applied:
 * If the AFC Champions League title holders or AFC Cup title holders were from associations ranked 1st to 6th, their association was allocated the same number of play-off slots, and they replace the lowest-seeded team from their association. Otherwise, their association was allocated one additional play-off slot, and they did not replace any team from their association (Articles 3.8, 3.9, and 3.10).
 * If both the AFC Champions League title holders and AFC Cup title holders were from the same association, which was allocated only one play-off slot, their association was allocated one additional play-off slot, and only the lowest-seeded team from their association was replaced as a result (Article 3.11).
 * The AFC Champions League and AFC Cup title holders were the lowest-seeded teams in the qualifying play-offs if they did not replace any team from their association (Article 3.12).
 * If any association ranked 1st to 6th did not fulfill the AFC Champions League criteria, they would have all their direct slots converted into play-off slots. The direct slots given up would be redistributed to the highest eligible association by the following criteria (Articles 3.13 and 3.14):
 * For each association, the maximum number of total slots was four, and the maximum number of direct slots was three (Articles 3.4 and 3.5).
 * If any association ranked 3rd to 6th was allocated one additional direct slot, one play-off slot was annulled and not redistributed.
 * If any association ranked 5th to 6th was allocated two additional direct slots, one play-off slot was annulled and not redistributed.
 * If any association ranked 7th to 10th did not fulfill the AFC Champions League criteria, they had their direct slot converted into a playoff slot. The direct slot given up was redistributed to the next association ranked 11th or 12th, whose play-off slot was annulled and not redistributed, or if neither was eligible, the highest eligible association by the same criteria mentioned above (Articles 3.16 and 3.17).
 * If any association with only play-off slot(s), including any association ranked 11th to 12th or those mentioned above, did not fulfill the minimum AFC Champions League criteria, the play-off slot(s) was annulled and not redistributed (Articles 3.19 and 3.20).
 * The maximum number of total slots for each association was one-third of eligible teams (excluding foreign teams) in the top division (Article 3.4). If this rule was applied, any direct slots given up would be redistributed by the same criteria as mentioned above, and play-off slots would be annulled and not redistributed (Article 9.10).
 * All participating teams had to be granted an AFC Champions League license and, apart from cup winners, finish in the top half of their top division (Articles 7.1 and 9.5). In the case that any association did not have enough teams that satisfied this criterion, any direct slots given up would be redistributed by the abovementioned criteria, and play-off slots would be annulled and not redistributed (Article 9.9).
 * If any team granted a license refused to participate, their direct or play-off slot was annulled and not redistributed (Article 9.11).

Association ranking
For the 2023–24 AFC Champions League, the associations were allocated slots according to the November 2021 AFC club competitions ranking, which took into account their performance in the AFC Champions League and the AFC Cup during the period between 2018 and 2021.


 * Notes

Teams
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.

Note: Only teams assured of a place are displayed.


 * Notes

Schedule
The schedule of the competition was as follows.

Top scorers
{{legend|silver|Team eliminated for this round.}} {{legend|#DDDDDD|Player is not in the team but the team is still active for this round.}}
 * Note
 * Goals scored in the qualifying play-offs and matches voided by AFC are not counted when determining top scorer (Regulations Article 64.4)