# 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)

## Draw
### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* Alt = Alternate
* SE = Special exempt
* PR = Protected ranking
* ITF = ITF entry
* JE = Junior exempt
* w/o = Walkover
* r = Retired
* d = Defaulted
* SR = Special ranking

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final |
| Q | Cem İlkel | 4 | 6 | 6$^7$ | | | | |
| Q | Joris De Loore | 6 | 3 | 7$^9$ | | | | |
| Q | Joris De Loore | 6 | 3 | 7$^9$ | Q | Joris De Loore | 6 | 6 |
| | | | | | | Filip Cristian Jianu | 3 | 2 |
| | Filip Cristian Jianu | 6 | 6 | | | Filip Cristian Jianu | 3 | 2 |
| 8 | Raphaël Collignon | 3 | 2 | | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | R Berankis | 2 | 6 | 7 | | | | | | | | | | | | | | |
| | GM Moroni | 6 | 1 | 5 | 1 | R Berankis | 2 | 7 | 6$^3$ | | | | | | | | | |
| Q | K de Schepper | 6 | 2 | 4 | Q | C İlkel | 6 | 5 | 7$^7$ | | | | | | | | | |
| Q | C İlkel | 4 | 6 | 6 | | | | | | Q | C İlkel | 6 | 6 | | | | | |
| | Elmar Ejupovic | 6 | 7 | | | | | | | | G Debru | 1 | 2 | | | | | |
| WC | P Sousa | 3 | 5 | | | E Ejupovic | 3 | 6 | 5 | | | | | | | | | |
| | G Debru | 2 | 6 | 7 | | G Debru | 6 | 4 | 7 | | | | | | | | | |
| 7 | M Valkusz | 6 | 1 | 5 | | | | | | | | | | Q | C İlkel | 4 | 6 | 6$^7$ |
| 3 | M Gigante | 6 | 7 | | | | | | | | | | | Q | J De Loore | 6 | 3 | 7$^9$ |
| | C Tabur | 3 | 5 | | 3 | M Gigante | 6 | 1 | 3 | | | | | | | | | |
| Q | D Prižmić | 7 | 6 | | Q | D Prižmić | 2 | 6 | 6 | | | | | | | | | |
| | P-H Herbert | 5 | 1 | | | | | | | Q | D Prižmić | 4 | 3 | | | | | |
| WC | G Oliveira | 6 | 7$^9$ | | | | | | | Q | J De Loore | 6 | 6 | | | | | |
| | L Wessels | 3 | 6$^7$ | | WC | G Oliveira | 4 | 4 | | | | | | | | | | |
| Q | J De Loore | 6 | 7$^{10}$ | | Q | J De Loore | 6 | 6 | | | | | | | | | | |
| 5 | A Dougaz | 2 | 6$^8$ | | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 6 | M Neuchrist | 7 | 7$^7$ | | | | | | | | | | | | | | |
| | L Neumayer | 5 | 6$^3$ | | 6 | M Neuchrist | 6 | 7$^9$ | | | | | | | | | |
| | V Vacherot | 6 | 4 | 1 | | J Domingues | 3 | 6$^7$ | | | | | | | | | |
| | J Domingues | 1 | 6 | 6 | | | | | | 6 | M Neuchrist | 3 | 6$^4$ | | | | |
| | FC Jianu | 3 | 6 | 7$^7$ | | | | | | | FC Jianu | 6 | 7$^7$ | | | | |
| Q | M Lajal | 6 | 3 | 6$^5$ | | FC Jianu | 6 | 6 | | | | | | | | | |
| | Lucas Gerch | 4 | 3 | | 4 | H Međedović | 2 | 3 | | | | | | | | | |
| 4 | H Međedović | 6 | 6 | | | | | | | | | | | | FC Jianu | 6 | 6 |
| 8 | R Collignon | 6 | 6 | | | | | | | | | | | 8 | R Collignon | 3 | 2 |
| WC | J Faria | 1 | 1 | | 8 | R Collignon | 6 | 7$^7$ | | | | | | | | | |
| | L Giustino | 6 | 3 | 6 | | L Giustino | 2 | 6$^5$ | | | | | | | | | |
| | Pol Martín Tiffon | 1 | 6 | 3 | | | | | | 8 | R Collignon | 6 | 7 | | | | |
| LL | E Leshem | 6 | 6 | | | | | | | LL | E Leshem | 4 | 5 | | | | |
| Q | A Kachmazov | 4 | 4 | | LL | E Leshem | 3 | 6 | 6 | | | | | | | | |
| | G Décamps | 6$^4$ | 1 | | 2 | J Clarke | 6 | 3 | 2 | | | | | | | | |
| 2 | J Clarke | 7$^7$ | 6 | | | | | | | | | | | | | | |