| Singles | |
|---|---|
| 2021 Antalya Challenger III | |
| Champion |  Nuno Borges |
| Runner-up |  Ryan Peniston |
| Score | 6–4, 6–3 |
Carlos Taberner was the defending champion [1] but was not eligible to compete in the tournament due to his ATP ranking.
Nuno Borges won the title after defeating Ryan Peniston 6–4, 6–3 in the final.
Cem İlkel (second round)
Ramkumar Ramanathan (quarterfinals) João Domingues (second round)
Duje Ajduković (quarterfinals)
Tseng Chun-hsin (first round) Nuno Borges (champion)
Geoffrey Blancaneaux (second round) Gonçalo Oliveira (first round, retired)| Semifinals | Final | ||||||||||||
 Javier Barranco Cosano | 4 | 62 | |||||||||||
| Ryan Peniston | 6 | 77 | |||||||||||
| Ryan Peniston | 4 | 3 | |||||||||||
| 6 | Nuno Borges | 6 | 6 | ||||||||||
| 6 | Nuno Borges | 6 | 6 | ||||||||||
| Eduard Esteve Lobato | 3 | 3 | |||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1/WC | C İlkel | 6 | 6 | ||||||||||||||||||||||||
| Alt | Y-h Hsu | 3 | 4 | 1/WC | C İlkel | 63 | 3 | ||||||||||||||||||||
| J Barranco Cosano | 77 | 6 | J Barranco Cosano | 77 | 6 | ||||||||||||||||||||||
| O Roca Batalla | 64 | 4 | J Barranco Cosano | 6 | 4 | 6 | |||||||||||||||||||||
| Q |  Mick Veldheer | 1 | 4 |  FC Jianu | 1 | 6 | 4 | ||||||||||||||||||||
| FC Jianu | 6 | 6 | FC Jianu | 65 | 6 | 6 | |||||||||||||||||||||
 M Zekić | 62 | 3 | 7 | G Blancaneaux | 77 | 4 | 0 | ||||||||||||||||||||
| 7 | G Blancaneaux | 77 | 6 | J Barranco Cosano | 4 | 62 | |||||||||||||||||||||
| 4 | D Ajduković | 6 | 5 | 7 | R Peniston | 6 | 77 | ||||||||||||||||||||
 N Chappell | 4 | 7 | 5 | 4 | D Ajduković | 6 | 6 | ||||||||||||||||||||
| Q | T Cação | 6 | 6 | Q | T Cação | 2 | 1 | ||||||||||||||||||||
| WC |  A Metreveli | 3 | 2 | 4 | D Ajduković | 2 | 7 | 62 | |||||||||||||||||||
| R Peniston | 2 | 6 | 6 | R Peniston | 6 | 5 | 77 | ||||||||||||||||||||
 N Fatić | 6 | 1 | 3 | R Peniston | 2 | 6 | 6 | ||||||||||||||||||||
 D Svrčina | 6 | 0 | D Svrčina | 6 | 4 | 2 | |||||||||||||||||||||
| 8 | G Oliveira | 4 | 0r | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 6 | N Borges | 6 | 6 | ||||||||||||||||||||||||
| E Kırkın | 4 | 3 | 6 | N Borges | 6 | 6 | |||||||||||||||||||||
 E Tiurnev | 65 | 7 | 3r | WC | Y Erel | 4 | 0 | ||||||||||||||||||||
| WC | Y Erel | 77 | 5 | 3 | 6 | N Borges | 6 | 6 | |||||||||||||||||||
 N Hardt | 6 | 6 | N Hardt | 2 | 4 | ||||||||||||||||||||||
 A Dougaz | 2 | 2 | N Hardt | 6 | 7 | ||||||||||||||||||||||
 R Bonadio | 64 | 6 | 1 | 3 | J Domingues | 4 | 5 | ||||||||||||||||||||
| 3 | J Domingues | 77 | 4 | 6 | 6 | N Borges | 6 | 6 | |||||||||||||||||||
| 5 | C-h Tseng | 2 | 7 | 67 | E Esteve Lobato | 3 | 3 | ||||||||||||||||||||
 F Misolic | 6 | 5 | 79 | F Misolic | 2 | 3 | |||||||||||||||||||||
| Alt |  D-h Lee | 2 | 3 | E Esteve Lobato | 6 | 6 | |||||||||||||||||||||
| Eduard Esteve Lobato | 6 | 6 | E Esteve Lobato | 6 | 6 | ||||||||||||||||||||||
| N Sánchez Izquierdo | 1 | 3 | 2 | R Ramanathan | 2 | 0 | |||||||||||||||||||||
| Q | Oliver Crawford | 6 | 6 | Q | O Crawford | 5 | 4 | ||||||||||||||||||||
| Q |  L Wessels | 2 | 3 | 2 | R Ramanathan | 7 | 6 | ||||||||||||||||||||
| 2 | R Ramanathan | 6 | 6 | ||||||||||||||||||||||||
Alexander Zverev was the defending champion, but chose not to participate this year.
Jozef Kovalík was the defending champion but lost in the quarterfinals to Carlos Taberner.
Albert Ramos Viñolas defeated Cameron Norrie in the final, 4–6, 6–3, 7–6(7–3) to win the singles tennis title at the 2021 Estoril Open. It marked his third career ATP Tour singles title, all of which have been on clay. Norrie was aiming to win his first ATP Tour title in his second final.
Andrey Rublev was the defending champion, but chose to not defend his title as he and other Russian Olympic athletes were sent to Yuzhno-Sakhalinsk for training sessions.
Miomir Kecmanović was the defending champion, but chose to compete at the Summer Olympics instead.
Pedro Sousa was the defending champion but chose not to defend his title.
Zdeněk Kolář and Andrea Vavassori were the defending champions but chose not to defend their title.
Nuno Borges was the defending champion but chose not to defend his title.
This was the first edition of the tournament.
Gastão Elias was the defending champion and successfully defended his title, defeating Nino Serdarušić 6–3, 6–4 in the final.
Jesper de Jong and Tim van Rijthoven were the defending champions but chose not to defend their title.
Gastão Elias was the two-time defending champion and successfully defended his title, defeating Alessandro Giannessi 7–6(7–4), 6–1 in the final.
Altuğ Çelikbilek was the defending champion but lost in the first round to Alejandro Moro Cañas.
Benjamin Bonzi was the defending champion but chose not to defend his title.
Alex Molčan was the defending champion but chose not to defend his title.
Thiago Monteiro was the defending champion but chose not to defend his title.
Andrey Rublev defeated Sebastian Korda in the final, 6–2, 6–3 to win the singles tennis title at the 2022 Gijón Open. It was his 12th ATP Tour singles title.
Brandon Nakashima was the defending champion but chose not to defend his title.
This was the first edition of the tournament.
Fernando Verdasco was the defending champion but chose not to defend his title.