| 1. Round | 23/02/2020 | Mito HollyHock | - | RB Omiya Ardija | 1:2 | ||||
| 5. Round | 15/07/2020 | Tochigi SC | - | RB Omiya Ardija | 1:0 |  |
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| 6. Round | 19/07/2020 | Ventforet Kofu | - | RB Omiya Ardija | 1:0 | ||||
| 7. Round | 25/07/2020 | RB Omiya Ardija | - | Matsumoto Yamaga | 1:0 | ||||
| 8. Round | 29/07/2020 | Zweigen Kanazawa | - | RB Omiya Ardija | 0:1 | ||||
| 10. Round | 08/08/2020 | Albirex Niigata | - | RB Omiya Ardija | 1:1 | ||||
| 29. Round | 25/10/2020 | RB Omiya Ardija | - | V-Varen Nagasaki | 0:0 | ||||
| 30. Round | 01/11/2020 | RB Omiya Ardija | - | FC Ryūkyū | 0:3 | ||||
| 31. Round | 04/11/2020 | Giravanz Kitakyushu | - | RB Omiya Ardija | 1:2 | |
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| 32. Round | 08/11/2020 | RB Omiya Ardija | - | Ventforet Kofu | 1:2 |  |
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| 34. Round | 15/11/2020 | RB Omiya Ardija | - | Zweigen Kanazawa | 1:0 | ||||
| 35. Round | 21/11/2020 | RB Omiya Ardija | - | FC Machida Zelvia | 0:0 | ||||
| 36. Round | 25/11/2020 | Thespakusatsu Gunma | - | RB Omiya Ardija | 1:2 | ||||
| 37. Round | 29/11/2020 | Avispa Fukuoka | - | RB Omiya Ardija | 1:0 | ||||
| 38. Round | 02/12/2020 | RB Omiya Ardija | - | Ehime FC | 3:3 | ||||
| 39. Round | 06/12/2020 | Júbilo Iwata | - | RB Omiya Ardija | 2:0 | ||||
| 40. Round | 13/12/2020 | RB Omiya Ardija | - | Renofa Yamaguchi | 3:1 |
Japan