| Singles | |
|---|---|
| 2018 Argentina Open | |
| Champion |  Dominic Thiem |
| Runner-up |  Aljaž Bedene |
| Score | 6–2, 6–4 |
| Draw | 28 (4 Q / 3 WC ) |
| Seeds | 8 |
Alexandr Dolgopolov was the defending champion, but withdrew before the tournament began.
Dominic Thiem won the title, defeating Aljaž Bedene in the final, 6–2, 6–4.
The top four seeds receive a bye into the second round.
Dominic Thiem (champion)
Pablo Carreño Busta (second round) Albert Ramos Viñolas (second round)
Fabio Fognini (second round)
Diego Schwartzman (quarterfinals)
Kyle Edmund (withdrew)
Pablo Cuevas (first round) Fernando Verdasco (second round)| Semifinals | Final | ||||||||||||
| 1 | Dominic Thiem | 6 | 6 | ||||||||||
 Gaël Monfils | 2 | 1 | |||||||||||
| 1 | Dominic Thiem | 6 | 6 | ||||||||||
| Aljaž Bedene | 2 | 4 | |||||||||||
| Aljaž Bedene | 6 | 2 | 6 | ||||||||||
| Federico Delbonis | 4 | 6 | 1 | ||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1 | D Thiem | 6 | 6 | ||||||||||||||||||||||||
| H Zeballos | 6 | 6 | H Zeballos | 4 | 3 | ||||||||||||||||||||||
| Q | M Cecchinato | 1 | 4 | 1 | D Thiem | 79 | 6 | ||||||||||||||||||||
| WC | N Kicker | 6 | 4 | 4 | G Pella | 67 | 4 | ||||||||||||||||||||
| G Pella | 2 | 6 | 6 | G Pella | 6 | 6 | |||||||||||||||||||||
| SE |  T Monteiro | 2 | 5 | 8 | F Verdasco | 2 | 4 | ||||||||||||||||||||
| 8 | F Verdasco | 6 | 7 | 1 | D Thiem | 6 | 6 | ||||||||||||||||||||
| G Monfils | 2 | 1 | |||||||||||||||||||||||||
| 4 | F Fognini | 3 | 3 | ||||||||||||||||||||||||
| Q | R Dutra Silva | 77 | 2 | 4 | L Mayer | 6 | 6 | ||||||||||||||||||||
| L Mayer | 64 | 6 | 6 | L Mayer | 4 | 6 | 3 | ||||||||||||||||||||
 D Lajović | 77 | 6 | G Monfils | 6 | 3 | 6 | |||||||||||||||||||||
| Q | F Bagnis | 64 | 1 | D Lajović | 4 | 3 | |||||||||||||||||||||
| G Monfils | 6 | 6 | G Monfils | 6 | 6 | ||||||||||||||||||||||
| 7 | P Cuevas | 1 | 4 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 5 | D Schwartzman | 6 | 6 | ||||||||||||||||||||||||
| PR | A Haider-Maurer | 4 | 3 | 5 | D Schwartzman | 3 | 6 | 6 | |||||||||||||||||||
| Q | T Bellucci | 6 | 6 | Q | T Bellucci | 6 | 3 | 2 | |||||||||||||||||||
| WC | P Cachin | 2 | 1 | 5 | D Schwartzman | 4 | 4 | ||||||||||||||||||||
 J Veselý | 0 | 3 | A Bedene | 6 | 6 | ||||||||||||||||||||||
| A Bedene | 6 | 6 | A Bedene | 3 | 7 | 6 | |||||||||||||||||||||
| 3 | A Ramos Viñolas | 6 | 5 | 1 | |||||||||||||||||||||||
| A Bedene | 6 | 2 | 6 | ||||||||||||||||||||||||
| LL |  G Elias | 6 | 6 | F Delbonis | 4 | 6 | 1 | ||||||||||||||||||||
| SE | R Carballés Baena | 2 | 4 | LL | G Elias | 65 | 66 | ||||||||||||||||||||
| F Delbonis | 77 | 6 | F Delbonis | 77 | 78 | ||||||||||||||||||||||
 F Mayer | 64 | 4 | F Delbonis | 6 | 7 | ||||||||||||||||||||||
| WC | C Berlocq | 3 | 3 | G García López | 3 | 5 | |||||||||||||||||||||
| G García López | 6 | 6 | G García López | 77 | 1 | 78 | |||||||||||||||||||||
| 2 | P Carreño Busta | 65 | 6 | 66 | |||||||||||||||||||||||
Tennys Sandgren (first round) Marco Cecchinato (qualified) Rogério Dutra Silva (qualified) Thomaz Bellucci (qualified) Gastão Elias (qualifying competition, lucky loser)
Casper Ruud (qualifying competition) Renzo Olivo (first round) Alessandro Giannessi (first round)| First round | Qualifying competition | ||||||||||||
| 1 | Tennys Sandgren | 1 | 2 | ||||||||||
| Facundo Bagnis | 6 | 6 | |||||||||||
| Facundo Bagnis | 67 | 6 | 6 | ||||||||||
| 5 | Gastão Elias | 79 | 1 | 1 | |||||||||
| Alt | João Souza | 6 | 3 | 0 | |||||||||
| 5 | Gastão Elias | 4 | 6 | 6 | |||||||||
| First round | Qualifying competition | ||||||||||||
| 2 | Marco Cecchinato | 6 | 6 | ||||||||||
| Guido Andreozzi | 4 | 3 | |||||||||||
| 2 | Marco Cecchinato | 6 | 77 | ||||||||||
| 6 | Casper Ruud | 3 | 64 | ||||||||||
| João Domingues | 1 | 3 | |||||||||||
| 6 | Casper Ruud | 6 | 6 | ||||||||||
| First round | Qualifying competition | ||||||||||||
| 3 | Rogério Dutra Silva | 69 | 6 | 2 | |||||||||
| Alt | Andrea Collarini | 711 | 3 | 1r | |||||||||
| 3 | Rogério Dutra Silva | 77 | 77 | ||||||||||
| Alt | Guilherme Clezar | 65 | 65 | ||||||||||
| Alt | Guilherme Clezar | 7 | 6 | ||||||||||
| 7 | Renzo Olivo | 5 | 0 | ||||||||||
| First round | Qualifying competition | ||||||||||||
| 4 | Thomaz Bellucci | 6 | 6 | ||||||||||
| WC | Juan Ignacio Galarza | 4 | 4 | ||||||||||
| 4 | Thomaz Bellucci | 6 | 6 | ||||||||||
| WC | Hernán Casanova | 2 | 4 | ||||||||||
| WC | Hernán Casanova | 77 | 6 | ||||||||||
| 8 | Alessandro Giannessi | 65 | 4 | ||||||||||
Tommy Robredo was the defending champion, but he chose to compete in the 2010 ABN AMRO World Tennis Tournament instead.
Juan Carlos Ferrero won in the final 6–1, 6–0 against Łukasz Kubot.
Tommy Robredo was the defending champion but withdrew due to leg injury.
Rafael Nadal defeated David Nalbandian in the final, 6–2, 6–3 to win the singles tennis title at the 2013 Brasil Open.
David Ferrer was the defending champion, and he successfully defended his title by defeating Stanislas Wawrinka in the final 6–4, 3–6, 6–1.
Diego Sebastián Schwartzman was the defending champion, but lost to Martín Alund on the Second Round. Uruguayan Wild Card Pablo Cuevas won the title over Argentinian Facundo Argüello, 7–6(8–6), 2–6, 6–4.
Fabio Fognini was the defending champion, but lost to Filip Krajinović in the second round.
Leonardo Mayer won the title, defeating David Ferrer in the final, 6–7(3–7), 6–1, 7–6(7–4).
Pablo Cuevas was the defending champion. He lost his title in the semifinals to Benoît Paire. Paire went on to win the title, defeating Tommy Robredo in the final, 7–6(9–7), 6–3.
Rafael Nadal was the defending champion, but lost to Dominic Thiem in the semifinals.
David Ferrer was the defending champion, but lost in the quarterfinals to Dominic Thiem.
Pablo Cuevas was the defending champion and successfully defended his title, defeating Pablo Carreño Busta in the final, 7–6(7–4), 6–3.
Two-time defending champion Novak Djokovic defeated Kei Nishikori in the final, 6–3 6–3 to win the men's singles tennis title at the 2016 Miami Open. Djokovic completed his record fourth Sunshine Double with the win, and won his record-equaling sixth Miami Open title. He did not lose a single set in the entire tournament.
Thomaz Bellucci was the defending champion but lost in the first round to Gastão Elias.
Diego Schwartzman was the defending champion but chose not to defend his title.
Dominic Thiem was the defending champion, but lost in the quarterfinals to Fernando Verdasco.
Rogério Dutra Silva was the defending champion but lost in the quarterfinals to Carlos Gómez-Herrera.
Two-time defending champion Rafael Nadal defeated Stefanos Tsitsipas in the final, 6–2, 6–1 to win the singles tennis title at the 2018 Barcelona Open. With the win, Nadal retained the ATP no. 1 singles ranking. It was Nadal's record-extending eleventh Barcelona Open title and his 20th ATP 500 title overall, equaling Roger Federer's record. It was Tsitsipas' maiden ATP Tour final.
Andrey Rublev was the defending champion, but lost in the quarterfinals to Robin Haase. This was Rublev's first tournament back on tour after missing three months due to a stress fracture in his back.
Dominic Thiem was the defending champion, but lost to Diego Schwartzman in the semifinals.
Diego Schwartzman was the defending champion, but he retired in the first round against Pablo Cuevas.
Marco Cecchinato was the defending champion but chose not to defend his title.