Kashima Antlers won the title for the first time, defeating Persepolis in the final, and qualified as the AFC representative at the 2018 FIFA Club World Cup in the United Arab Emirates.

It marked the second season in a row without title holders after Jeonbuk Hyundai Motors were disqualified in 2017 as a result of their involvement in a match-fixing scandal in 2016.

The eight winners of the play-off round advanced to the group stage to join the 24 direct entrants.

All losers in each round from associations with only play-off slots entered the AFC Cup group stage.

[15] The draw for the group stage was held on 6 December 2017, 16:30 MYT (UTC+8), at the AFC House in Kuala Lumpur, Malaysia.

[1] The bracket was decided after the draw for the quarter-finals, which was held on 23 May 2018, 16:00 MYT (UTC+8), at the AFC House in Kuala Lumpur, Malaysia.