| Singles | |
|---|---|
| 2023 Oeiras Indoors II | |
| Champion |  Arthur Fils |
| Runner-up |  Joris De Loore |
| Score | 6–1, 7–6(7–4) |
Joris De Loore was the defending champion [1] but lost in the final to Arthur Fils.
Fils won the title after defeating De Loore 6–1, 7–6(7–4) in the final.
Ričardas Berankis (semifinals)
Jay Clarke (second round)
Matteo Gigante (first round) Arthur Fils (champion)
Hamad Međedović (first round) Harold Mayot (first round)
Nikolás Sánchez Izquierdo (first round)
Steven Diez (first round)| Semifinals | Final | ||||||||||||
| 1 | Ričardas Berankis | 5 | 3 | ||||||||||
| 4 | Arthur Fils | 7 | 6 | ||||||||||
| 4 | Arthur Fils | 6 | 77 | ||||||||||
| SE | Joris De Loore | 1 | 64 | ||||||||||
| Pierre-Hugues Herbert | 2 | 4 | |||||||||||
| SE | Joris De Loore | 6 | 6 | ||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1 | R Berankis | 77 | 6 | ||||||||||||||||||||||||
 M Valkusz | 63 | 1 | 1 | R Berankis | 5 | 6 | 6 | ||||||||||||||||||||
| Q |  M Lajal | 4 | 4r |  L Gerch | 7 | 4 | 4 | ||||||||||||||||||||
| Lucas Gerch | 6 | 5 | 1 | R Berankis | 7 | 78 | |||||||||||||||||||||
 E Karlovskiy | 0 | 0r | Q |  D Prižmić | 5 | 66 | |||||||||||||||||||||
| Q | D Prižmić | 6 | 3 | Q | D Prižmić | 2 | 6 | 6 | |||||||||||||||||||
| Q | S Fanselow | 6 | 3 | 6 | Q | S Fanselow | 6 | 2 | 2 | ||||||||||||||||||
| 6 | H Mayot | 2 | 6 | 4 | 1 | R Berankis | 5 | 3 | |||||||||||||||||||
| 4 | A Fils | 6 | 0 | 6 | 4 | A Fils | 7 | 6 | |||||||||||||||||||
| L Wessels | 3 | 6 | 2 | 4 | A Fils | 7 | 6 | ||||||||||||||||||||
 J Domingues | 2 | 3 | Q |  C İlkel | 5 | 2 | |||||||||||||||||||||
| Q | C İlkel | 6 | 6 | 4 | A Fils | 6 | 6 | ||||||||||||||||||||
 L Neumayer | 2 | 2 | M Neuchrist | 3 | 1 | ||||||||||||||||||||||
| WC | G Oliveira | 6 | 6 | WC | G Oliveira | 64 | 3 | ||||||||||||||||||||
| M Neuchrist | 4 | 6 | 7 | M Neuchrist | 77 | 6 | |||||||||||||||||||||
| 8 | S Diez | 6 | 3 | 5 | |||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 7 | N Sánchez Izquierdo | 63 | 3 | ||||||||||||||||||||||||
| WC | P Sousa | 77 | 6 | WC | P Sousa | 3 | 7 | 6 | |||||||||||||||||||
| Q |  G Décamps | 61 | 77 | 4 | P Martín Tiffon | 6 | 5 | 4 | |||||||||||||||||||
| Pol Martín Tiffon | 77 | 65 | 6 | WC | P Sousa | 1 | 4 | ||||||||||||||||||||
 A Dougaz | 4 | 5 | P-H Herbert | 6 | 6 | ||||||||||||||||||||||
 FC Jianu | 6 | 7 | FC Jianu | 6 | 3 | 2 | |||||||||||||||||||||
| P-H Herbert | 3 | 6 | 6 | P-H Herbert | 3 | 6 | 6 | ||||||||||||||||||||
| 3 | M Gigante | 6 | 4 | 4 | P-H Herbert | 2 | 4 | ||||||||||||||||||||
| 5 | H Međedović | 64 | 3 | SE | J De Loore | 6 | 6 | ||||||||||||||||||||
| SE | J De Loore | 77 | 6 | SE | J De Loore | 6 | 6 | ||||||||||||||||||||
 V Vacherot | 5 | 4 | R Collignon | 4 | 3 | ||||||||||||||||||||||
| R Collignon | 7 | 6 | SE | J De Loore | 6 | 6 | |||||||||||||||||||||
| Q | Elmar Ejupovic | 4 | 5 | L Giustino | 2 | 4 | |||||||||||||||||||||
| L Giustino | 6 | 7 | L Giustino | 6 | 77 | ||||||||||||||||||||||
| WC | J Faria | 4 | 3 | 2 | J Clarke | 3 | 64 | ||||||||||||||||||||
| 2 | J Clarke | 6 | 6 | ||||||||||||||||||||||||
Tiago Fernandes was the defending champion, having defeated Sean Berman in the 2010 final. He chose not to defend his title.
Jiří Veselý won the title defeating Luke Saville 6–0, 6–3, in the final. The player from Czech Republic won every match in straight sets.
Dutch players Justin Eleveld and Jannick Lupescu chose to not defend their 2010 title, when they defeated Kevin Krawietz and Dominik Schulz in the final.
Filip Horanský and Jiří Veselý won this year's title, by defeating Ben Wagland and Andrew Whittington 6–4, 6–4 in the final match.
Agustín Velotti was the defending champion but was not eligible to participate.
Bjorn Fratangelo won this event, defeating 14th-seed Dominic Thiem 3–6, 6–3, 8–6 in the final.
Tristan Lamasine was the defending champion but chose not to defend his title.
Ivan Dodig was the defending champion but chose not to defend his title.
Johan Brunström and Frederik Nielsen were the defending champions but chose not to defend their title.
Henri Laaksonen was the defending champion and successfully defended his title by defeating Ruben Bemelmans 7–5, 6–3 in the final.
Sanchai and Sonchat Ratiwatana were the defending champions but only Sanchai Ratiwatana chose to defend his title, partnering Peng Hsien-yin. Ratiwatana lost in the first round to Masahiro Fukuda and Masamichi Imamura.
Kimmer Coppejans was the defending champion but lost in the first round to Tallon Griekspoor.
Sam Groth and Adil Shamasdin were the defending champions but only Shamasdin chose to defend his title, partnering Frank Dancevic. Dancevic and Shamasdin withdrew in the semifinals.
Jo-Wilfried Tsonga was the defending champion, but due to injury did not defend his title.
Alex Bolt and Max Purcell were the defending champions but only Purcell chose to defend his title, partnering Lloyd Harris. Purcell lost in the semifinals to Joris De Loore and Marc Polmans.
Joris De Loore and Frederik Nielsen were the defending champions but chose not to defend their title.
This was the first edition of the tournament.
Dominic Stricker was the defending champion but lost in the first round to Joris De Loore.
Tomáš Macháč was the defending champion but lost in the second round to Denis Yevseyev.
Márton Fucsovics was the defending champion but chose not to defend his title.
Andrey Rublev defeated Emil Ruusuvuori in the final, 6–4, 6–4 to win the singles tennis title at the 2024 ATP Hong Kong Tennis Open. It was his 15th ATP Tour singles title.
Otto Virtanen was the defending champion but lost in the semifinals to Arthur Rinderknech.
Dimitar Kuzmanov was the defending champion but chose not to defend his title.