The 2018 Brasil Open was a tennis tournament played on indoor clay courts. It was the 18th edition of the Brasil Open, and part of the ATP World Tour 250 series of the 2018 ATP World Tour. It took place from February 26 through March 4, 2018, in São Paulo, Brazil.
| Country | Player | Ranking1 | Seed | |
|---|---|---|---|---|
 Spain | Albert Ramos Viñolas | 19 | 1 | |
 Italy | Fabio Fognini | 21 | 2 | |
| Pablo Cuevas | 33 | 3 | ||
 France | Gaël Monfils | 39 | 4 | |
 Argentina | Leonardo Mayer | 49 | 5 | |
| Argentina | Guido Pella | 55 | 6 | |
| Tennys Sandgren | 60 | 7 | ||
| Argentina | Federico Delbonis | 63 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry from the qualifying draw:
Jiří Veselý → replaced by Carlos Berlocq| Country | Player | Country | Player | Rank1 | Seed | |
|---|---|---|---|---|---|---|
| Pablo Cuevas | Argentina | Horacio Zeballos | 55 | 1 | ||
| Hans Podlipnik Castillo |  Belarus | Andrei Vasilevski | 97 | 2 | ||
| Argentina | Guillermo Durán | Argentina | Andrés Molteni | 110 | 3 | |
| Wesley Koolhof |  New Zealand | Artem Sitak | 120 | 4 |
The following pairs received wildcards into the doubles main draw:
The following pairs received entry as alternates:
Pedro Bernardi / Thiago Monteiro Fabrício Neis / Renzo OlivoSee main article: 2018 Brasil Open – Singles.
Fabio Fognini def. Nicolás Jarry, 1–6, 6–1, 6–4[1]See main article: 2018 Brasil Open – Doubles.
Federico Delbonis / Máximo González def. Wesley Koolhof / Artem Sitak, 6–4, 6–2.