2018 San Luis Open Challenger Tour – Singles

Andrej Martin was the defending champion but chose not to defend his title.

Marcelo Arévalo won the title after defeating Roberto Cid Subervi 6–3, 6–7(3–7), 6–4 in the final.

Seeds
• # 🇮🇹 Paolo Lorenzi (first round)

• # 🇦🇹 Gerald Melzer (first round, retired)

• # 🇩🇪 Yannick Hanfmann (second round)

• # 🇧🇷 Thomaz Bellucci (second round)

• # 🇩🇴 Víctor Estrella Burgos (first round)

• # 🇺🇸 Evan King (first round)

• # 🇺🇸 Mitchell Krueger (first round)

• # 🇷🇸 Peđa Krstin (second round)