2023 Open de Oeiras

The 2023 Open de Oeiras was a professional tennis tournament played on clay courts. It was the eighth edition of the tournament which was part of the 2023 ATP Challenger Tour. It took place in Oeiras, Portugal between 17 and 23 April 2023.

Seeds

 * 1 Rankings are as of 10 April 2023.

Other entrants
The following players received wildcards into the singles main draw:
 * Henrique Rocha
 * Pedro Sousa
 * Duarte Vale

The following player received entry into the singles main draw as a special exempt:
 * 🇭🇺 Zsombor Piros

The following player received entry into the singles main draw as an alternate:
 * João Domingues

The following players received entry from the qualifying draw:
 * 🇷🇴 Cezar Crețu
 * Jaime Faria
 * 🇬🇧 Billy Harris
 * 🇪🇸 Pablo Llamas Ruiz
 * 🇪🇸 Daniel Mérida
 * 🇨🇿 Petr Nouza

The following player received entry as a lucky loser:
 * 🇩🇪 Henri Squire

Singles

 * 🇭🇺 Zsombor Piros def. 🇦🇷 Juan Manuel Cerúndolo 6–3, 6–4.

Doubles

 * 🇷🇴 Victor Vlad Cornea / Franko Škugor def. 🇧🇷 Marcelo Demoliner / 🇮🇹 Andrea Vavassori 7–6(7–2), 7–6(7–4).