| Men's singles | |
|---|---|
| 2023 Iași Open | |
| Champion |  Hugo Gaston |
| Runner-up |  Bernabé Zapata Miralles |
| Score | 3–6, 6–0, 6–4 |
Felipe Meligeni Alves was the defending champion [1] but chose not to defend his title.
Hugo Gaston won the title after defeating Bernabé Zapata Miralles 3–6, 6–0, 6–4 in the final.
Bernabé Zapata Miralles (final)
Radu Albot (first round)
Tomáš Macháč (first round, retired)
Zsombor Piros (first round)
Cristian Garín (semifinals) Hugo Gaston (champion) Enzo Couacaud (first round) Zdeněk Kolář (second round)| Semifinals | Final | ||||||||||||
| 1/WC | Bernabé Zapata Miralles | 2 | 7 | 6 | |||||||||
| 5 | Cristian Garín | 6 | 5 | 3 | |||||||||
| 1/WC | Bernabé Zapata Miralles | 6 | 0 | 4 | |||||||||
| 6 | Hugo Gaston | 3 | 6 | 6 | |||||||||
| 6 | Hugo Gaston | 6 | 6 | ||||||||||
| Alt |  Steven Diez | 4 | 4 | ||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1/WC | B Zapata Miralles | 6 | 6 | ||||||||||||||||||||||||
 A Dougaz | 4 | 3 | 1/WC | B Zapata Miralles | 6 | 6 | |||||||||||||||||||||
| D Svrčina | 77 | 6 | D Svrčina | 3 | 4 | ||||||||||||||||||||||
| Q |  Sebastian Gima | 63 | 2 | 1/WC | B Zapata Miralles | 6 | 3 | 6 | |||||||||||||||||||
| J Menšík | 7 | 6 | J Menšík | 1 | 6 | 2 | |||||||||||||||||||||
| Q | K Jacquet | 5 | 4 | J Menšík | 6 | 6 | |||||||||||||||||||||
| Q |  Andrey Chepelev | 4 | 6 | 5 | 8 | Z Kolář | 2 | 2 | |||||||||||||||||||
| 8 | Z Kolář | 6 | 3 | 7 | 1/WC | B Zapata Miralles | 2 | 7 | 6 | ||||||||||||||||||
| 4 | Z Piros | 2 | 6 | 62 | 5 | C Garín | 6 | 5 | 3 | ||||||||||||||||||
| T Atmane | 6 | 3 | 77 | T Atmane | 1 | 5 | |||||||||||||||||||||
 Edoardo Lavagno | 4 | 3 | R Bonadio | 6 | 7 | ||||||||||||||||||||||
| R Bonadio | 6 | 6 | R Bonadio | 4 | 6 | 63 | |||||||||||||||||||||
| Alt |  V Vacherot | 77 | 7 | 5 | C Garín | 6 | 4 | 77 | |||||||||||||||||||
 J De Loore | 64 | 5 | Alt | V Vacherot | 62 | 2 | |||||||||||||||||||||
 DN Mădăraș | 5 | 2 | 5 | C Garín | 77 | 6 | |||||||||||||||||||||
| 5 | C Garín | 7 | 6 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 6 | H Gaston | 4 | 0 | ||||||||||||||||||||||||
| Alt |  M Zekić | 6 | 1r | 6 | H Gaston | 77 | 6 | ||||||||||||||||||||
| PR |  P Cuevas | 6 | 6 | PR | P Cuevas | 65 | 1 | ||||||||||||||||||||
| G Onclin | 2 | 3 | 6 | H Gaston | 6 | 3 | 6 | ||||||||||||||||||||
| LL | M Vrbenský | 6 | 6 |  V Sachko | 0 | 6 | 3 | ||||||||||||||||||||
| Q |  Juan Bautista Otegui | 2 | 3 | LL | M Vrbenský | 1 | 2 | ||||||||||||||||||||
| V Sachko | 65 | 6 | 3 | V Sachko | 6 | 6 | |||||||||||||||||||||
| 3 | T Macháč | 77 | 4 | 0r | 6 | H Gaston | 6 | 6 | |||||||||||||||||||
| 7 | E Couacaud | 2 | 1 | Alt | S Diez | 4 | 4 | ||||||||||||||||||||
| WC | FC Jianu | 6 | 6 | WC | FC Jianu | 6 | 4 | 3 | |||||||||||||||||||
| Q |  K Ivanovski | 4 | 77 | 6 | Q | K Ivanovski | 3 | 6 | 6 | ||||||||||||||||||
| ND Ionel | 6 | 64 | 2 | Q | K Ivanovski | 4 | 3 | ||||||||||||||||||||
| Q | Àlex Martí Pujolràs | 1 | 1 | Alt | S Diez | 6 | 6 | ||||||||||||||||||||
| Alt | S Diez | 6 | 6 | Alt | S Diez | 6 | 6 | ||||||||||||||||||||
| JP Ficovich | 6 | 6 | JP Ficovich | 3 | 4 | ||||||||||||||||||||||
| 2 | R Albot | 3 | 3 | ||||||||||||||||||||||||
Stan Wawrinka was the two-time defending champion but lost to Márton Fucsovics in the quarterfinals.
Salvatore Caruso was the defending champion and chose not to defend his title.
Gaël Monfils was the defending champion, but chose not to defend his title.
Aslan Karatsev won his first ATP Tour singles title, defeating Lloyd Harris in the final, 6–3, 6–2 to win the men's singles tennis title at the 2021 Dubai Tennis Championships. Karatsev became the second wildcard in the tournament's history to win the men's singles title. Harris was the first qualifier to reach the final of the Dubai Tennis Championships.
Carlos Taberner was the defending champion but chose not to defend his title.
Tommy Robredo was the defending champion but chose not to defend his title.
Bernabé Zapata Miralles was the defending champion but chose not to defend his title.
Jo-Wilfried Tsonga was the reigning champion from when the tournament was last held in 2019, but chose not to participate this year.
Carlos Alcaraz was the defending champion but chose not to defend his title.
This was the first edition of the tournament.
Félix Auger-Aliassime defeated Stefanos Tsitsipas in the final, 6–4, 6–2. It was his maiden ATP Tour singles title, following eight runner-up finishes in prior finals.
Defending champion Stefanos Tsitsipas defeated Alejandro Davidovich Fokina in the final, 6–3, 7–6(7–3) to win the singles tennis title at the 2022 Monte-Carlo Masters. He became the sixth player to win consecutive titles at the Monte-Carlo Masters in the Open Era. The win also earned him his second Masters 1000 title and his eighth career singles title overall.
Sebastián Báez defeated Frances Tiafoe in the final, 6–3, 6–2 to win the singles tennis title at the 2022 Estoril Open. It was his maiden ATP Tour title.
Bernabé Zapata Miralles was the defending champion but lost in the quarterfinals to Andrej Martin.
Bernabé Zapata Miralles was the defending champion but chose not to defend his title.
Sebastian Korda was the defending champion but chose not to defend his title.
Tomás Barrios Vera was the defending champion but chose not to defend his title.
Pedro Martínez was the defending champion but lost in the first round to Kimmer Coppejans.
Nicolás Jarry defeated Tomás Martín Etcheverry in the final, 6–7(5–7), 7–6(7–5), 6–2 to win the singles tennis title at the 2023 Chile Open. This was Jarry's first ATP title since 2019.
Bernabé Zapata Miralles was the defending champion but chose not to defend his title.