| Singles | |
|---|---|
| 2021 Challenger de Santiago | |
| Champion |  Sebastián Báez |
| Runner-up |  Marcelo Tomás Barrios Vera |
| Score | 6–3, 7–6(7–4) |
Hugo Dellien was the defending champion [1] but chose not to defend his title.
Sebastián Báez won the title after defeating Marcelo Tomás Barrios Vera 6–3, 7–6(7–4) in the final.
Roberto Carballés Baena (second round)
Andrej Martin (second round)
Pedro Sousa (second round) Facundo Bagnis (withdrew) Jozef Kovalík (first round)
Daniel Altmaier (second round)
Kimmer Coppejans (second round) Alejandro Tabilo (first round)| Semifinals | Final | ||||||||||||
| Marcelo Tomás Barrios Vera | 77 | 1 | |||||||||||
 Felipe Meligeni Alves | 65 | 1r | |||||||||||
| Marcelo Tomás Barrios Vera | 3 | 64 | |||||||||||
| Sebastián Báez | 6 | 77 | |||||||||||
| Sebastián Báez | 6 | 77 | |||||||||||
 Juan Pablo Varillas | 1 | 63 | |||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1 | R Carballés Baena | 2 | 6 | 77 | |||||||||||||||||||||||
| T Bellucci | 6 | 2 | 60 | 1 | R Carballés Baena | 6 | 65 | 68 | |||||||||||||||||||
| WC | G Lama | 6 | 6 | WC | G Lama | 2 | 77 | 710 | |||||||||||||||||||
| TM Etcheverry | 4 | 2 | WC | G Lama | 64 | 65 | |||||||||||||||||||||
| MT Barrios Vera | 4 | 6 | 77 | MT Barrios Vera | 77 | 77 | |||||||||||||||||||||
 C Lindell | 6 | 1 | 64 | MT Barrios Vera | 6 | 6 | |||||||||||||||||||||
| O Luz | 3 | 1 | 7 | K Coppejans | 4 | 4 | |||||||||||||||||||||
| 7 | K Coppejans | 6 | 6 | MT Barrios Vera | 77 | 1 | |||||||||||||||||||||
| 3 | P Sousa | 6 | 6 | F Meligeni Alves | 65 | 1r | |||||||||||||||||||||
| LL | R Matos | 4 | 3 | 3 | P Sousa | 4 | 2 | ||||||||||||||||||||
| F Meligeni Alves | 5 | 6 | 7 | F Meligeni Alves | 6 | 6 | |||||||||||||||||||||
| Q | J Menezes | 7 | 3 | 5 | F Meligeni Alves | 6 | 7 | ||||||||||||||||||||
 E Benchetrit | 6 | 6 | Q | N Kicker | 1 | 5 | |||||||||||||||||||||
 G Blancaneaux | 4 | 4 | E Benchetrit | 2 | 4 | ||||||||||||||||||||||
| Q | N Kicker | 6 | 6 | Q | N Kicker | 6 | 6 | ||||||||||||||||||||
| 5 | J Kovalík | 2 | 3 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 6 | D Altmaier | 6 | 6 | ||||||||||||||||||||||||
| G Andreozzi | 4 | 3 | 6 | D Altmaier | 4 | 6 | 3 | ||||||||||||||||||||
| Alt | C Ugo Carabelli | 6 | 6 | Alt | C Ugo Carabelli | 6 | 3 | 6 | |||||||||||||||||||
| Q |  M Cuevas | 4 | 0 | Alt | C Ugo Carabelli | 2 | 1 | ||||||||||||||||||||
| WC |  H Rune | 2 | 4 | S Báez | 6 | 6 | |||||||||||||||||||||
| S Báez | 6 | 6 | S Báez | 7 | 6 | ||||||||||||||||||||||
| A Collarini | 4 | 4 | Q | G Villanueva | 5 | 2 | |||||||||||||||||||||
| Q | G Villanueva | 6 | 6 | S Báez | 6 | 77 | |||||||||||||||||||||
| 8 | A Tabilo | 3 | 2 | JP Varillas | 1 | 63 | |||||||||||||||||||||
| WC | N Jarry | 6 | 6 | WC | N Jarry | 6 | 6 | ||||||||||||||||||||
| N Álvarez | 3 | 6 | 6 | N Álvarez | 3 | 4 | |||||||||||||||||||||
| P Sakamoto | 6 | 4 | 3 | WC | N Jarry | 2 | 4 | ||||||||||||||||||||
| JP Varillas | 6 | 3 | 7 | JP Varillas | 6 | 6 | |||||||||||||||||||||
| R Olivo | 4 | 6 | 5 | JP Varillas | 6 | 69 | 6 | ||||||||||||||||||||
| G Oliveira | 62 | 5 | 2 | A Martin | 4 | 711 | 4 | ||||||||||||||||||||
| 2 | A Martin | 77 | 7 | ||||||||||||||||||||||||
Jack Sock was the defending champion, but participated in the men's main draw, as he was ineligible to defend his title.
Márton Fucsovics was the defending champion but chose not to defend his title.
Ričardas Berankis was the defending champion but chose not to defend his title.
Filip Krajinović was the defending champion but chose not to defend his title.
Filip Krajinović was the defending champion but chose not to defend his title.
Víctor Estrella Burgos was the defending champion but lost in the first round to Federico Delbonis.
Diego Schwartzman was the defending champion, but he retired in the first round against Pablo Cuevas.
Hugo Dellien was the defending champion but chose not to defend his title.
Nikoloz Basilashvili was the defending champion and successfully defended his title, defeating Andrey Rublev in the final, 7–5, 4–6, 6–3. En route to doing so, Basilashvili saved two match points against Alexander Zverev in the semifinals.
Martin Kližan was the defending champion but lost in the first round to Matthias Bachinger.
Roger Federer was the two-time defending champion and successfully defended his title, defeating Alex de Minaur in the final, 6–2, 6–2. He did not lose a single set in the entire tournament. The victory made Federer the first player in ATP history to win 10 same tournament titles on two different surfaces. It was his 103rd and final ATP title before announcing his retirement in 2022.
Diego Schwartzman defeated Francisco Cerúndolo in the final, 6–1, 6–2 to win the men's singles tennis title at the 2021 Argentina Open.
Norbert Gombos was the defending champion but lost in the second round to Filip Horanský.
Kamil Majchrzak was the defending champion but chose not to defend his title.
Hugo Dellien was the defending champion but chose not to defend his title.
Daniel Elahi Galán was the defending champion but chose not to defend his title.
Casper Ruud defeated the defending champion Diego Schwartzman in the final, 5–7, 6–2, 6–3 to win the singles title at the 2022 Argentina Open.
Sebastián Báez defeated Frances Tiafoe in the final, 6–3, 6–2 to win the singles tennis title at the 2022 Estoril Open. It was his maiden ATP Tour title.
Sebastian Korda was the defending champion but chose not to defend his title.
Hugo Dellien was the defending champion but chose not to defend his title.