The Semi-marathon de Saint-Witz is a road race held in Saint-Witz, a commune in Val-d'Oise, north of Paris. It takes place in late March, a time when mornings in this region of Île-de-France can still be cold, suggesting that a warm layer before the start is advisable. The event offers more than just its namesake distance; while the half marathon is the main event, participants can also opt for shorter races of 5 km, 10 km, and 11.5 km, alongside children’s and junior races.
The event begins in Saint-Witz and is organized by COSMSW. Established in 1979, it ranks among the longer-standing half marathons in France. The race accommodates walkers, broadening participation beyond those focused on half-marathon times. Families, younger runners, walkers, local club members, and individuals seeking a shorter road race can all find a place in this event.