| Club: | Adana Demirspor |
| Season: | 2020–21 |
| Chairman: | Murat Sancak |
| Manager: | Ümit Özat (until 13 December) Cüneyt Dumlupınar (from 15 December to 19 February) Samet Aybaba (from 22 February) |
| Stadium: | Adana 5 Ocak Stadium New Adana Stadium |
| League: | TFF First League |
| League Result: | 1st (promoted) |
| Cup1: | Turkish Cup |
| Cup1 Result: | Round of 16 |
| League Topscorer: | Hasan Kılıç (12) |
| Season Topscorer: | Hasan Kılıç (12) |
| Prevseason: | 2019–20 |
| Nextseason: | 2021–22 |
The 2020–21 season was Adana Demirspor's 81st season in existence and third consecutive in the TFF First League, the second tier of Turkish football. They also competed in the Turkish Cup. Adana Demirspor achieved promotion.
| Player | Transferred from | Fee | Date | Source | ||
|---|---|---|---|---|---|---|
| Göztepe | ||||||
| Beşiktaş | Free | |||||
| Honvéd | ||||||
| Bursaspor | Free | |||||
| Bnei Yehuda | Free | |||||
| Sancaktepe | Free | |||||
| Gaziantep | Free | |||||
| Yeni Malatyaspor | Loan | |||||
| Galatasaray | Loan | [1] | ||||
| İstanbul Başakşehir U19 | ||||||
| Amiens | ||||||
| İstanbul Başakşehir | Free | |||||
| Alanyaspor | Loan | |||||
| Denizlispor | Free | |||||
| Mersin BB Meski | Free | |||||
| Erzurumspor | Free | |||||
| Balıkesirspor | €200,000 | |||||
| Dinamo Tbilisi | Loan | |||||
| KuPS | Free | |||||
| Ankara Keçiörengücü | €471,000 | |||||
| Fenerbahçe | Loan | |||||
| İstanbul Başakşehir | Loan |
| Player | Transferred to | Fee | Date | Source | ||
|---|---|---|---|---|---|---|
| Zorya Lugansk | Free | |||||
| Adanaspor | ||||||
| Konyaspor | €200,000 | |||||
| Tuzla City | Free | |||||
| Tuzlaspor | ||||||
| Bandırmaspor | ||||||
| Released | ||||||
| Ankaraspor | ||||||
| Tuzlasspor | Free | |||||
| İstanbulspor | Free | |||||
| Tuzlaspor | ||||||
| Kozan Spor FK | Loan | |||||
| Vicenza | Free | [2] | ||||
| Cracovia | Free | |||||
| KuPS | Free | |||||
See main article: 2020–21 TFF First League.
See main article: 2020–21 Turkish Cup.