The 2023 Porto Open was a professional tennis tournament played on hard courts. It was the third edition of the tournament which was part of the 2023 ATP Challenger Tour. It took place in Porto, Portugal between 31 July and 6 August 2023.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 France | Quentin Halys | 66 | 1 | |
| France | Benjamin Bonzi | 107 | 2 | |
| France | Hugo Grenier | 122 | 3 | |
 Italy | Luca Nardi | 154 | 4 | |
| Italy | Mattia Bellucci | 175 | 5 | |
 United States | Emilio Nava | 177 | 6 | |
| France | Antoine Escoffier | 191 | 7 | |
 Lithuania | Ričardas Berankis | 199 | 8 |
The following players received wildcards into the singles main draw:
The following player received entry into the singles main draw using a protected ranking:
The following players received entry from the qualifying draw:
Kenny de Schepper Lucas PoullainSee main article: 2023 Porto Open – Singles.
Luca Nardi def. João Sousa 5–7, 6–4, 6–1.See main article: 2023 Porto Open – Doubles.
Toshihide Matsui / Kaito Uesugi def. 
Rithvik Choudary Bollipalli / Arjun Kadhe 6–7(5–7), 6–3, [10–5].