# 2023 NÖ Open – Singles

Jozef Kovalík was the defending champion but lost in the first round to Henri Squire.
Vít Kopřiva won the title after defeating Sumit Nagal 6–2, 6–4 in the final.

## Seeds

* Albert Ramos Viñolas (quarterfinals)
* Jurij Rodionov (second round)
* Maximilian Marterer (semifinals)
* Flavio Cobolli (semifinals)
* Jozef Kovalík (first round)
* Ivan Gakhov (second round)
* Dalibor Svrčina (second round)
* Vitaliy Sachko (second 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 |
| | Sumit Nagal | 6 | 6 | | | |
| 4 | Flavio Cobolli | 3 | 4 | | | |
| 4 | Flavio Cobolli | 3 | 4 | Sumit Nagal | 2 | 4 |
| | | | | Vít Kopřiva | 6 | 6 |
| 3 | Maximilian Marterer | 3 | 3 | Vít Kopřiva | 6 | 6 |
| | Vít Kopřiva | 6 | 6 | | | |

### 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 |
| 1 | A Ramos Viñolas | 6 | 7$^7$ | | | | | | | | | | | | | | |
| | F Misolic | 4 | 6$^2$ | | 1 | A Ramos Viñolas | 6 | 6 | | | | | | | | | |
| WC | Sandro Kopp | 3 | 4 | | Q | G Melzer | 3 | 2 | | | | | | | | | |
| Q | G Melzer | 6 | 6 | | | | | | | 1 | A Ramos Viñolas | 6$^6$ | 3 | | | | |
| | S Nagal | 6 | 6 | | | | | | | | S Nagal | 7$^8$ | 6 | | | | |
| Q | D Masur | 1 | 2 | | | S Nagal | 7$^7$ | 3 | 6 | | | | | | | | |
| | L Neumayer | 6$^2$ | 6$^1$ | | 8 | V Sachko | 6$^2$ | 6 | 3 | | | | | | | | |
| 8 | V Sachko | 7$^7$ | 7$^7$ | | | | | | | | | | | | S Nagal | 6 | 6 |
| 4 | F Cobolli | 6 | 7 | | | | | | | | | | | 4 | F Cobolli | 3 | 4 |
| | J Sels | 3 | 5 | | 4 | F Cobolli | 5 | | | | | | | | | | |
| Q | Jeremy Jahn | 7$^7$ | 4 | 6$^4$ | | H Laaksonen | 0$^r$ | | | | | | | | | | |
| | H Laaksonen | 6$^5$ | 6 | 7$^7$ | | | | | | 4 | F Cobolli | 6 | 6 | | | | |
| WC | N Oberleitner | 6$^4$ | 6 | 3 | | | | | | | H Squire | 1 | 2 | | | | |
| WC | L Miedler | 7$^7$ | 2 | 6 | WC | L Miedler | 6 | 3 | 4 | | | | | | | | |
| | H Squire | 6$^3$ | 6 | 6 | | H Squire | 4 | 6 | 6 | | | | | | | | |
| 5 | J Kovalík | 7$^7$ | 2 | 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 | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 6 | I Gakhov | 7 | 6 | | | | | | | | | | | | | | | |
| Q | B Hassan | 5 | 4 | | 6 | I Gakhov | 7$^7$ | 4 | 6$^4$ | | | | | | | | | |
| | R Molleker | 5 | 4 | | | S Rodríguez Taverna | 6$^4$ | 6 | 7$^7$ | | | | | | | | | |
| | S Rodríguez Taverna | 7 | 6 | | | | | | | | S Rodríguez Taverna | 6 | 4 | 6$^1$ | | | | |
| | Timo Stodder | 1 | 6 | 6 | | | | | | 3 | M Marterer | 4 | 6 | 7$^7$ | | | | |
| | S Diez | 6 | 2 | 1 | | T Stodder | 6$^9$ | 1 | | | | | | | | | | |
| Q | L Rosol | 4 | 6 | 3 | 3 | M Marterer | 7$^{11}$ | 6 | | | | | | | | | | |
| 3 | M Marterer | 6 | 3 | 6 | | | | | | | | | | | 3 | M Marterer | 3 | 3 |
| 7 | D Svrčina | 1 | 6 | 6 | | | | | | | | | | | | V Kopřiva | 6 | 6 |
| Q | M Möller | 6 | 4 | 1 | 7 | D Svrčina | 6 | 4 | 2 | | | | | | | | | |
| | D Kuzmanov | 6$^3$ | 6 | 7 | | D Kuzmanov | 2 | 6 | 6 | | | | | | | | | |
| | D Novak | 7$^7$ | 2 | 5 | | | | | | | D Kuzmanov | 1 | 1 | | | | | |
| | V Kopřiva | 6 | 7$^7$ | | | | | | | | V Kopřiva | 6 | 6 | | | | | |
| | Z Kolář | 2 | 6$^4$ | | | V Kopřiva | 7 | 2 | 6 | | | | | | | | | |
| | Elmar Ejupovic | 6$^4$ | 6 | 4 | 2 | J Rodionov | 5 | 6 | 4 | | | | | | | | | |
| 2 | J Rodionov | 7$^7$ | 2 | 6 | | | | | | | | | | | | | | |