2023 Estoril Open – Singles

Casper Ruud defeated Miomir Kecmanović in the final, 6–2, 7–6(7–3) to win the singles tennis title at the 2023 Estoril Open. The victory marked Ruud's tenth career singles title and his first of the season. Kecmanović was bidding to secure his second career singles title.

Sebastián Báez was the defending champion, but lost in the quarterfinals to Ruud.

Seeds
The top four seeds received a bye into the second round. • #🇳🇴 Casper Ruud (champion)

• #🇵🇱 Hubert Hurkacz (second round)

• #🇪🇸 Alejandro Davidovich Fokina (quarterfinals)

• #🇪🇸 Roberto Bautista Agut (second round)

• #🇦🇷 Sebastián Báez (quarterfinals)

• #🇷🇸 Miomir Kecmanović (final)

• #🇦🇷 Diego Schwartzman (first round)

• #🇺🇸 Ben Shelton (second round)

Seeds
• # 🇭🇺 Fábián Marozsán (qualifying competition)

• # 🇦🇹 Sebastian Ofner (qualified)

• # 🇬🇧 Ryan Peniston (first round)

• # 🇸🇰 Jozef Kovalík (first round)

• # 🇰🇿 Timofey Skatov (qualifying competition)

• # 🇺🇦 Oleksii Krutykh (first round)

• # 🇨🇿 Dalibor Svrčina (first round)

• # 🇧🇦 Damir Džumhur (first round)

Qualifiers
• # 🇮🇹 Alessandro Giannessi

• # 🇦🇹 Sebastian Ofner

• # Henrique Rocha

• # Pedro Sousa