| Club: | Gaziantep F.K. |
| Season: | 2020–21 |
| Ownertitle: | Owner |
| Owner: | Sanko Holding |
| Chrtitle: | Chairman |
| Chairman: | Mehmet Büyükekşi |
| Mgrtitle: | Manager |
| Manager: | Marius Șumudică (until 10 January 2021) Ricardo Sá Pinto (from 20 January 2021) |
| Stadium: | Gaziantep Arena |
| League: | Süper Lig |
| League Result: | 5th |
| Cup1: | Turkish Cup |
| Cup1 Result: | Round of 16 |
| League Topscorer: | Alexandru Maxim (11) |
| Season Topscorer: | Alexandru Maxim (12) |
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| Prevseason: | 2019–20 |
| Nextseason: | 2021–22 |
The 2020–21 season is Gaziantep F.K.'s 32nd season in existence and the club's 2nd consecutive season in the top flight of Turkish football. In addition to the domestic league, Gaziantep will participate in this season's editions of the Turkish Cup. The season covers the period from July 2020 to 30 June 2021.
| scope=col | Player | Transferred from | scope=col; style="width: 65px;" | Fee | scope=col | Date | scope=col | Source | ||
|---|---|---|---|---|---|---|---|---|---|---|
| 15 | TBD |
| scope=col | Player | Transferred to | scope=col; style="width: 65px;" | Fee | scope=col | Date | scope=col | Source | ||
|---|---|---|---|---|---|---|---|---|---|---|
| 15 | TBD |
See main article: 2020–21 Süper Lig.
See main article: 2020–21 Turkish Cup.