| Competition: | First League of the Republika Srpska |
| Season: | 2020–21 |
| Dates: | 8 August 2020 – 29 May 2021 |
| Winners: | Rudar Prijedor 3rd First League title |
| Promoted: | Rudar Prijedor Leotar |
| Relegated: | Jedinstvo Brčko |
| Matches: | 240 |
| Total Goals: | 608 |
| League Topscorer: | Bojan Marković Nikola Mojović Ognjen Stjepanović (14 goals each) |
| Prevseason: | 2019–20 |
| Nextseason: | 2021–22 |
The 2020–21 First League of the Republika Srpska was the twenty-sixth season of the First League of the Republika Srpska, the second tier football league of Bosnia and Herzegovina, since its original establishment and the nineteenth as a second-tier league. The season began on 8 August 2020 and ended on 29 May 2021.