2018 Rio Open – Singles

Dominic Thiem was the defending champion, but lost in the quarterfinals to Fernando Verdasco.

Diego Schwartzman won the title, defeating Verdasco in the final, 6–2, 6–3.

Seeds
• # Marin Čilić (second round)

• #🇦🇹 Dominic Thiem (quarterfinals)

• #🇪🇸 Pablo Carreño Busta (second round)

• #🇪🇸 Albert Ramos Viñolas (second round)

• #🇮🇹 Fabio Fognini (semifinals)

• #🇦🇷 Diego Schwartzman (champion)

• # Pablo Cuevas (quarterfinals)

• #🇪🇸 Fernando Verdasco (final)

Seeds
• # 🇪🇸 Roberto Carballés Baena (qualified)

• # 🇮🇹 Marco Cecchinato (qualified)

• # Gastão Elias (qualifying competition, lucky loser)

• # 🇦🇷 Carlos Berlocq (qualified)

• # Pedro Sousa (first round)

• # 🇫🇷 Corentin Moutet (qualified)

• # 🇦🇹 Sebastian Ofner (first round)

• # 🇮🇹 Alessandro Giannessi (qualifying competition)

Qualifiers
• # 🇪🇸 Roberto Carballés Baena

• # 🇮🇹 Marco Cecchinato

• # 🇫🇷 Corentin Moutet (withdrew due to a right knee injury)

• # 🇦🇷 Carlos Berlocq

Lucky losers

 * 1)  Gastão Elias