| Date: | 12–18 February |
| Edition: | 21st |
| Category: | ATP World Tour 250 series |
| Prize Money: | $546,680 |
| Draw: | 28S/16D |
| Surface: | clay |
| Location: | Buenos Aires, Argentina |
| Champs: |  Dominic Thiem |
| Champd: |  Andrés Molteni / Horacio Zeballos |
| Main Name: | ATP Buenos Aires |
The 2018 Argentina Open was a men's tennis tournament played on outdoor clay courts. It was the 21st edition of the ATP Buenos Aires event, and part of the ATP World Tour 250 series of the 2018 ATP World Tour. It took place in Buenos Aires, Argentina, from February 12 through 18, 2018.
| Event | W | F | SF | QF | Round of 16 | Round of 32 | width=85 | Q | width=85 | Q2 | width=85 | Q1 |
| Singles | 250 | 150 | 90 | 45 | 20 | 0 | 12 | 6 | 0 | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubles | 0 |
| Event | W | F | SF | QF | Round of 16 | Round of 32 | width=85 | Q2 | width=85 | Q1 |
| Singles | $97,470 | $51,355 | $27,810 | $15,840 | $9,335 | $5,530 | $2,490 | $1,240 | ||
| Doubles | $29,610 | $15,570 | $8,430 | $4,830 | $2,830 | |||||
| Doubles prize money per team | ||||||||||
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
| Austria | Dominic Thiem | 6 | 1 | |
 Spain | Pablo Carreño Busta | 10 | 2 | |
| Spain | Albert Ramos Viñolas | 21 | 3 | |
 Italy | Fabio Fognini | 22 | 4 | |
| Argentina | Diego Schwartzman | 24 | 5 | |
 United Kingdom | Kyle Edmund | 26 | 6 | |
| Pablo Cuevas | 32 | 7 | ||
| Spain | Fernando Verdasco | 40 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry as special exempts:
The following players received entry using a protected ranking:
The following players received entry from the qualifying draw:
Guillermo García López
Alexandr Dolgopolov → replaced by Florian Mayer Kyle Edmund → replaced by Gastão Elias Paolo Lorenzi → replaced by 
Dušan Lajović| Country | Player | Country | Player | Rank1 | Seed | |
|---|---|---|---|---|---|---|
 Colombia | Juan Sebastián Cabal | Colombia | Robert Farah | 35 | 1 | |
 Mexico | Santiago González | Julio Peralta | 57 | 2 | ||
| Nikola Mektić | Austria | Alexander Peya | 80 | 3 | ||
| Argentina | Andrés Molteni | Argentina | Horacio Zeballos | 84 | 4 |
The following pairs received wildcards into the doubles main draw:
See main article: 2018 Argentina Open – Singles.
Dominic Thiem defeated Aljaž Bedene, 6–2, 6–4See main article: 2018 Argentina Open – Doubles.
Andrés Molteni / Horacio Zeballos defeated Juan Sebastián Cabal / Robert Farah, 6–3, 5–7, [10–3]
