| 2023 Upper Austria Open | |
|---|---|
| Date | 8–14 May |
| Edition | 2nd |
| Surface | Clay |
| Location | Mauthausen, Austria |
| Champions | |
| Singles | |
 Hamad Međedović | |
| Doubles | |
 Romain Arneodo /  Sam Weissborn | |
The 2023 Danube Upper Austria Open was a professional tennis tournament played on clay courts. It was the second edition of the tournament which was part of the 2023 ATP Challenger Tour. It took place in Mauthausen, Austria between 8 and 14 May 2023.
| Country | Player | Rank1 | Seed |
|---|---|---|---|
| AUT | Dominic Thiem | 93 | 1 |
 FRA | Hugo Gaston | 106 | 2 |
 ARG | Facundo Bagnis | 116 | 3 |
 NED | Gijs Brouwer | 122 | 4 |
| AUT | Filip Misolic | 126 | 5 |
| AUT | Sebastian Ofner | 130 | 6 |
 SUI | Leandro Riedi | 156 | 7 |
| AUT | Dennis Novak | 159 | 8 |
The following players received wildcards into the singles main draw:
Sandro Kopp Gerald Melzer Lukas Neumayer The following players received entry into the singles main draw as alternates:
The following players received entry from the qualifying draw:
Mirza Bašić 
Marius Copil 
Lucas Gerch Hendrik Jebens Matthias Ujvary Damien Wenger Hamad Međedović def. Filip Misolic 6–2, 6–7(5–7), 6–4. Romain Arneodo / Sam Weissborn def. Constantin Frantzen / Hendrik Jebens 6–4, 6–2.
