| Date: | 2 – 8 January |
| Edition: | 1st |
| Surface: | Hard (indoor) |
| Location: | Oeiras, Portugal |
| Champs: |  Joris De Loore |
| Champd: |  Victor Vlad Cornea /  Petr Nouza |
| After Year: | 2023 |
| After Name: | Oeiras Indoors II |
The 2023 Oeiras Indoors was a professional tennis tournament played on hard courts. It was the 1st edition of the tournament which was part of the 2023 ATP Challenger Tour. It took place in Oeiras, Portugal from 2 to 8 January 2023.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Lithuania | Ričardas Berankis | 168 | 1 | |
 United Kingdom | Jay Clarke | 240 | 2 | |
 Italy | Matteo Gigante | 250 | 3 | |
 Serbia | Hamad Međedović | 255 | 4 | |
 Tunisia | Aziz Dougaz | 273 | 5 | |
 Austria | Maximilian Neuchrist | 274 | 6 | |
 Hungary | Máté Valkusz | 275 | 7 | |
| Belgium | Raphaël Collignon | 280 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry from the qualifying draw:
The following player received entry as a lucky loser:
See main article: 2023 Oeiras Indoors – Singles.
Joris De Loore def. Filip Cristian Jianu 6–3, 6–2.See main article: 2023 Oeiras Indoors – Doubles.
Victor Vlad Cornea / Petr Nouza def. 
Jonathan Eysseric / Pierre-Hugues Herbert 6–3, 7–6(7–3).
