# 2023 Porto Open – Singles

Altuğ Çelikbilek was the two-time defending champion but lost in the second round to Antoine Escoffier.
Luca Nardi won the title after defeating João Sousa 5–7, 6–4, 6–1 in the final.

## Seeds

* Quentin Halys (first round)
* Benjamin Bonzi (first round)
* Hugo Grenier (first round)
* Luca Nardi (champion)
* Mattia Bellucci (first round)
* Emilio Nava (second round)
* Antoine Escoffier (semifinals)
* Ričardas Berankis (first round)

## 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 | Final | Final | Final | Final | Final |
| | Jules Marie | 6$^4$ | 0 | | | | | |
| WC | João Sousa | 7$^7$ | 6 | | | | | |
| WC | João Sousa | 7$^7$ | 6 | WC | João Sousa | 7 | 4 | 1 |
| | | | | 4 | Luca Nardi | 5 | 6 | 6 |
| 4 | Luca Nardi | 7$^7$ | 6 | 4 | Luca Nardi | 5 | 6 | 6 |
| 7 | Antoine Escoffier | 6$^3$ | 4 | | | | | |

### 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 | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | Q Halys | 5 | 5 | | | | | | | | | | | | | | | |
| WC | G Elias | 7 | 7 | | WC | G Elias | 4 | 3 | | | | | | | | | | |
| | Jules Marie | 6 | 6 | | | J Marie | 6 | 6 | | | | | | | | | | |
| | B Lock | 3 | 4 | | | | | | | | J Marie | 3 | 7$^9$ | 6 | | | | |
| Q | J Domingues | 2 | 6 | 3 | | | | | | | D Yevseyev | 6 | 6$^7$ | 4 | | | | |
| | D Yevseyev | 6 | 3 | 6 | | D Yevseyev | 3 | 6 | 7 | | | | | | | | | |
| Q | J Härteis | 6$^3$ | 6$^2$ | | 6 | Em Nava | 6 | 3 | 5 | | | | | | | | | |
| 6 | Em Nava | 7$^7$ | 7$^7$ | | | | | | | | | | | | | J Marie | 6$^4$ | 0 |
| 3 | H Grenier | 4 | 3 | | | | | | | | | | | | WC | J Sousa | 7$^7$ | 6 |
| Q | J Faria | 6 | 6 | | Q | J Faria | 7$^7$ | 4 | 4 | | | | | | | | | |
| PR | P-H Herbert | 6 | 6 | | PR | P-H Herbert | 6$^1$ | 6 | 6 | | | | | | | | | |
| | L Lokoli | 4 | 4 | | | | | | | PR | P-H Herbert | 6$^4$ | 2 | | | | | |
| Q | K de Schepper | 4 | 4 | | | | | | | WC | J Sousa | 7$^7$ | 6 | | | | | |
| | A Kachmazov | 6 | 6 | | | A Kachmazov | 2 | 2 | | | | | | | | | | |
| WC | J Sousa | 6$^5$ | 6 | 6 | WC | J Sousa | 6 | 6 | | | | | | | | | | |
| 5 | M Bellucci | 7$^7$ | 4 | 4 | | | | | | | | | | | | | | |

### 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 |
| 8 | R Berankis | 6 | 4 | 6$^5$ | | | | | | | | | | | | | |
| | P Gojowczyk | 2 | 6 | 7$^7$ | | P Gojowczyk | 6 | 3 | 2 | | | | | | | | |
| | A Andreev | 6 | 7$^7$ | | | A Andreev | 2 | 6 | 6 | | | | | | | | |
| | Dominik Palán | 3 | 6$^2$ | | | | | | | | A Andreev | 4 | 3 | | | | |
| | G Oliveira | 6 | 6 | | | | | | | 4 | L Nardi | 6 | 6 | | | | |
| Q | Lucas Poullain | 4 | 0 | | | G Oliveira | 4 | 6 | 3 | | | | | | | | |
| | N Mejía | 6 | 2 | 3 | 4 | L Nardi | 6 | 3 | 6 | | | | | | | | |
| 4 | L Nardi | 3 | 6 | 6 | | | | | | | | | | 4 | L Nardi | 7$^7$ | 6 |
| 7 | A Escoffier | 6 | 6 | | | | | | | | | | | 7 | A Escoffier | 6$^3$ | 4 |
| | L Giustino | 3 | 4 | | 7 | A Escoffier | 6 | 7$^{11}$ | | | | | | | | | |
| | F Ferreira Silva | 4 | 7$^8$ | 3 | | A Çelikbilek | 4 | 6$^9$ | | | | | | | | | |
| | A Çelikbilek | 6 | 6$^6$ | 6 | | | | | | 7 | A Escoffier | 6 | 6 | | | | |
| WC | H Rocha | 6 | 4 | 6 | | | | | | | S Diez | 3 | 4 | | | | |
| Q | R Strombachs | 4 | 6 | 4 | WC | H Rocha | 3 | 2 | | | | | | | | | |
| | S Diez | 6 | 6 | | | S Diez | 6 | 6 | | | | | | | | | |
| 2 | B Bonzi | 4 | 4 | | | | | | | | | | | | | | |