| 2023 Open de Oeiras II | |
|---|---|
| Date | 15–20 May |
| Edition | 9th |
| Surface | Clay |
| Location | Oeiras, Portugal |
| Champions | |
| Singles | |
 Facundo Díaz Acosta | |
| Doubles | |
 Luke Johnson /  Sem Verbeek | |
The 2023 Open de Oeiras II was a professional tennis tournament played on clay courts. It was the ninth edition of the tournament which was part of the 2023 ATP Challenger Tour. It took place in Oeiras, Portugal between 15 and 20 May 2023.
| Country | Player | Rank1 | Seed |
|---|---|---|---|
| ARG | Pedro Cachin | 68 | 1 |
 FRA | Hugo Gaston | 110 | 2 |
 MDA | Radu Albot | 112 | 3 |
 ECU | Emilio Gómez | 116 | 4 |
| ARG | Facundo Bagnis | 123 | 5 |
 AUS | Aleksandar Vukic | 127 | 6 |
| ARG | Facundo Díaz Acosta | 134 | 7 |
| AUS | Rinky Hijikata | 139 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry into the singles main draw as alternates:
The following players received entry from the qualifying draw:
Facundo Díaz Acosta def. Aleksandar Vukic 6–4, 6–3. Luke Johnson / Sem Verbeek def. 
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