The 21 km de Blagnac is a flat half marathon held in Blagnac, adjacent to Toulouse. The event also features a 10 km race and children's races. It typically takes place in March, though the specific date may be confirmed later. The 10 km race is open to runners and Nordic walkers, and the children's race covers 1,075 metres. The half marathon consists of two laps of the 10 km course, with an additional 1.1 km loop to complete the 21.1 km distance.
The course offers a distinct Blagnac character, passing the Aeroscopia aviation museum and running alongside aircraft like the Concorde, Caravelle, and A380. It also crosses Georges Brassens square and the Odyssud and Grand Noble parks. Aid stations and medical support are provided along the route and at the finish. Pacers are available for the half marathon. This long-standing, well-attended event draws thousands of participants to the roads of Blagnac.