The 1920–21 season was the 2nd official football season for the club. They competed against 9 other teams in the Istanbul Sports League. As the defending champions, they came 1st place in their group and defeated Darüssafaka in the final, earning their 2nd ever championship.
| 1920–21 season | |
|---|---|
| President |  Fuat Balkan |
| Manager | Şeref Bey |
| Stadium | Dolmabahçe Field |
| Istanbul Sports League | 1st |
Season
editIn the Istanbul Sports League there were 2 groups: Group A and Group B. Beşiktaş was in group A.
Group A
edit| Pos | Club |
| 1 | Beşiktaş J.K. |
| 2 | Hilal S.K. |
| 3 | Kumkapı S.K. |
| 4 | Altınörs S.K. |
| 5 | Türkgücü |
Final
edit| 1921 | Beşiktaş | 2 – 0 | Darüşşafaka | Istanbul, Ottoman Empire |
| Hüsnü, İhsan Celal | www.macanilari.com/getir.php?fid=191919204610 | Stadium: Taksim Stadium Attendance: ??? Referee: ??? |