La Mouss'terlinoise is a Sunday race held in Mousterlin, within the Fouesnant area of Brittany. It is centered on the local school, not a major race brand. The primary event covers 10.1 km, with separate starts for middle schoolers, adults, and children throughout the morning.
The Parents' Association of the Mousterlin school organizes the race. Entry fees support school projects, including cultural trips, sports outings, and nature discovery activities. The event saw strong local participation, with 930 runners registered for the 10.1 km race. Morgan L’Helguen won the men's race by 24 seconds under clear skies and spring-like weather.