| 2025 Brest Challenger | |
|---|---|
| Date | 20–26 October |
| Edition | 10th |
| Surface | Hard (indoor) |
| Location | Brest, France |
| Champions | |
| Singles | |
 Hugo Gaston | |
| Doubles | |
 Sander Gillé /  Sem Verbeek | |
The 2025 Brest Open Groupe Vert was a professional tennis tournament played on hard courts. It was the tenth edition of the tournament which was part of the 2025 ATP Challenger Tour. It took place in Brest, France between 20 and 26 October 2025.
| Country | Player | Rank1 | Seed |
|---|---|---|---|
 SRB | Laslo Djere | 79 | 1 |
 ITA | Luca Nardi | 83 | 2 |
| FRA | Hugo Gaston | 97 | 3 |
 ESP | |||
 USA | Eliot Spizzirri | 111 | 5 |
 FIN | Otto Virtanen | 116 | 6 |
| USA | |||
| ITA | Francesco Passaro | 141 | 8 |
 ARG | Marco Trungelliti | 142 | 9 |
The following players received wildcards into the singles main draw:
Dan Added Hugo Gaston Maé MaligeThe following player received entry into the singles main draw using a protected ranking:
The following player received entry into the singles main draw as a special exempt:
The following players received entry into the singles main draw as alternates:
The following players received entry from the qualifying draw:
Jaime Faria 
Arthur Fery 
Jonáš Forejtek Lucas Poullain Clément Tabur 
Alexey Vatutin The following player received entry as a lucky loser:
Hugo Gaston def. Eliot Spizzirri 2–6, 6–2, 6–1. Sander Gillé / Sem Verbeek def. Théo Arribagé / Albano Olivetti 7–6(7–5), 7–6(7–4).