The Serbian Football Championship season of 1920–21 was the second championship organised by the Serbian Football Federation (Srpski loptački savez) after the 1919–20 season. Played among the clubs from the territory of the city of Belgrade, the Belgrade Football Subassociation.
First League (1. Razred)
edit| Pos | Team | Pld | W | D | L | GF | GA | GD | Pts |
|---|---|---|---|---|---|---|---|---|---|
| 1 | BSK Belgrade | 9 | 6 | 2 | 1 | 20 | 9 | +11 | 14 |
| 2 | SK Jugoslavija | 9 | 7 | 0 | 2 | 21 | 7 | +14 | 14 |
| 3 | BUSK | 9 | 3 | 1 | 5 | 10 | 16 | −6 | 7 |
| 4 | Vardar Belgrade | 9 | 3 | 1 | 5 | 7 | 12 | −5 | 7 |
| 5 | Konkordija Belgrade | 5 | 2 | 0 | 3 | 7 | 12 | −5 | 4 |
| 6 | Soko Belgrade | 9 | 2 | 0 | 7 | 9 | 27 | −18 | 4 |
Source: rsssf.org
Second Leagues
editBanat League
Participating:
- Obilić Veliki Bečkerek
- Vašaš Veliki Bečkerek
- Viktorija Veliki Bečkerek
- ŽSE Žombolj
- ŽTK Žombolj
- Šveboše Žombolj
- DSK Debeljača
- KAC Velika Kikinda
Provincial League - Župa 1
Participating:
- Vojvodina Novi Sad
- NAK Novi Sad
- NSK Zemun
- ASK Zemun
- PSK Pančevo
- RSK Ruma
Provincial League - Župa 2
Participating:
- Zora Bijeljina
- Podrinje Bijeljina
- Jedinstvo Brčko
- Sloga Brčko
- Građanski Sremska Mitrovica
- Srpski SK Sremska Mitrovica
- Sloga Šabac
- Srpski mač Valjevo
Provincial League - Župa 2
Participating:
- Jedinstvo Vranje
- Moravac Leskovac
- Jug Bogdan Prokuplje
- Zlatibor Užice
- Šumadija Kragujevac
- PSK Požarevac