| Date: | 29 November – 5 December |
| Edition: | 3rd |
| Surface: | Clay |
| Location: | Antalya, Turkey |
| Champs: | Nuno Borges |
| Champd: |  Riccardo Bonadio / Giovanni Fonio |
| Main Name: | Antalya Challenger |
| Before Year: | 2021 |
| Before Name: | Antalya Challenger II |
| After Name: | Antalya Challenger IV |
| After Year: | 2021 |
The 2021 Antalya Challenger III was a professional tennis tournament played on clay courts. It was the third edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Antalya, Turkey between 29 November and 5 December 2021.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Turkey | Cem İlkel | 145 | 1 | |
 India | Ramkumar Ramanathan | 222 | 2 | |
| João Domingues | 245 | 3 | ||
| Duje Ajduković | 247 | 4 | ||
| Tseng Chun-hsin | 251 | 5 | ||
| Nuno Borges | 262 | 6 | ||
 France | Geoffrey Blancaneaux | 280 | 7 | |
| Gonçalo Oliveira | 288 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry into the singles main draw as alternates:
The following players received entry from the qualifying draw:
See main article: 2021 Antalya Challenger III – Singles.
Ryan Peniston 6–4, 6–3.See main article: 2021 Antalya Challenger III – Doubles.
Riccardo Bonadio / Giovanni Fonio def. Hsu Yu-hsiou / Tseng Chun-hsin 3–6, 6–2, [12–10].
