| Season | 2021 |
|---|---|
| Dates | 13 March – 5 December |
| Champions | Roasso Kumamoto (1st title) |
| Promoted | Roasso Kumamoto Iwate Grulla Morioka |
| Relegated | No relegation |
| Matches played | 210 |
| Goals scored | 533 (2.54 per match) |
| Top goalscorer | Shota Kawanishi, FC Gifu (13 goals) |
| Biggest home win | Azul Claro Numazu v Vanraure Hachinohe 7-2 |
| Highest scoring | Gainare Tottori v Nagano Parceiro 1-8 Azul Claro Numazu v Vanraure Hachinohe 7-2 |
| Longest winning run | Roasso Kumamoto 7 (28/08/21 - 16/10/2021) |
| Longest unbeaten run | Roasso Kumamoto 12 (13/06/21 - 24/10/2021) |
| Highest attendance | 11,314 Roasso Kumamoto 2–0 FC Gifu (5 December 2021) |
| Lowest attendance | 264 Fukushima United FC 2–1 Iwate Grulla Morioka (26 May 2021) |
| Total attendance | 401,776 |
| Average attendance | 1,913 |
← 2020 2022 →
All statistics correct as of complete. | |
The 2021 J3 League, referred to as the 2021 Meiji Yasuda J3 League (Japanese: 2021 明治安田生命J3リーグ, Hepburn: 2021 Meiji Yasuda Seimei J3 Rīgu) for sponsorship reasons, was the 8th season of J3 League under its current name.
Roasso Kumamoto won the J3 title for the first time in their history, in their debut campaign at the J3 League, just three years after being relegation from the J2 League. They were promoted to the 2022 J2 League alongside Iwate Grulla Morioka. Iwate team won promotion for the J2 League for the first time.