J.LEAGUE announced the competition format of the 2021 MEIJI YASUDA J2 LEAGUE. More details will be announced as soon as determined.
| Competition | Schedule and number of matches | Competition format |
| MEIJI YASUDA J2 LEAGUE (22 teams) | Saturday 27 February – Sunday 5 December, 42 rounds/462 matches | Home and Away round-robin competition |
* There is a possibility of that the schedule may change.
■Promotion and relegation rules between J1 LEAGUE and J2 LEAGUE
● The bottom four clubs of J1 LEAGUE shall be relegated to J2 LEAGUE and the top two clubs of J2 LEAGUE shall be promoted to J1 LEAGUE
● J1/J2 Play-Offs shall not be held
● J2 clubs that have not received a J.LEAGUE club license cannot be promoted, and will not be replaced by third or lower place club
■Promotion and relegation rules between J2 LEAGUE and J3 LEAGUE
● The bottom four clubs of the J2 LEAGUE shall be relegated to J3 LEAGUE and the top two clubs of J3 LEAGUE shall be promoted to J2 LEAGUE
● J3 clubs that have not received a J.LEAGUE club license cannot be promoted and will not be replaced by third or lower place club
