The Bois-Guillaume Half Marathon is a road race held in mid-October in Bois-Guillaume, a town near Rouen in Normandy. The primary event is a 21.1 km half marathon. A 10 km race is also held that morning, alongside a Joëlette Cup for teams running with a person with a disability. Both the half marathon and 10 km begin at the Espace Guillaume le Conquérant. The main races are popular and can sell out. The 10 km is open to a broad range of participants, from beginners to experienced runners, including youth and seniors.
The half marathon course consists of two 10 km loops. It includes urban sections within Bois-Guillaume and a portion that goes through the Forêt Verte. This design offers more variety than a simple town-centre race while maintaining a straightforward format for participants and observers. The Joëlette Cup covers the 10 km distance and has no entry fee. The race also supports Octobre Rose, allowing runners to contribute to the league against cancer. A partner village with food vendors is located behind the Espace Guillaume le Conquérant.