| 2025 Open de Rennes | |
|---|---|
| Date | 8–14 September |
| Edition | 19th |
| Surface | Hard (Indoor) |
| Location | Rennes, France |
| Champions | |
| Singles | |
 Hugo Gaston | |
| Doubles | |
 Patrik Niklas-Salminen /  Matěj Vocel | |
The 2025 Open de Rennes was a professional tennis tournament played on hard courts. It was the 19th edition of the tournament and part of the 2025 ATP Challenger Tour. It took place in Rennes, France between 8 and 14 September 2025.
| Country | Player | Rank1 | Seed |
|---|---|---|---|
| FRA | Hugo Gaston | 125 | 1 |
 SUI | Stan Wawrinka | 146 | 2 |
| FRA | Harold Mayot | 152 | 3 |
| FRA | Titouan Droguet | 159 | 4 |
| FRA | |||
| FRA | Sascha Gueymard Wayenburg | 206 | 6 |
 ITA | Federico Cinà | 210 | 7 |
| FRA | Arthur Bouquier | 215 | 8 |
The following players received wildcards into the singles main draw:
Sean Cuenin Daniel Jade Maé MaligeThe following players received entry into the singles main draw as alternates:
Grégoire Barrère 
Vadym UrsuThe following players received entry from the qualifying draw:
Enzo Couacaud Kenny de Schepper Maxime Janvier 
Cannon Kingsley Leo Raquillet
Nikolay VylegzhaninThe following players received entry as lucky losers:
Robin Catry Egor Gerasimov Hugo Gaston def. Stan Wawrinka 6–4, 6–4. Patrik Niklas-Salminen / Matěj Vocel def. 
Hendrik Jebens / Albano Olivetti 6–3, 6–3.