2023 Oeiras Indoors – Singles

This was the first edition of the tournament.

Joris De Loore won the title after defeating Filip Cristian Jianu 6–3, 6–2 in the final.

Seeds
• # 🇱🇹 Ričardas Berankis (second round)

• # 🇬🇧 Jay Clarke (second round)

• # 🇮🇹 Matteo Gigante (second round)

• # 🇷🇸 Hamad Međedović (second round)

• # 🇹🇳 Aziz Dougaz (first round)

• # 🇦🇹 Maximilian Neuchrist (quarterfinals)

• # 🇭🇺 Máté Valkusz (first round)

• # 🇧🇪 Raphaël Collignon (semifinals)