Sven Nys is a former professional cyclist competing in cyclo-cross and mountain bike. With two world championships, seven world cups, and over 140 competitive victories, he is considered one of the best cyclo-cross racers of his generation, and remains a prominent figure in cyclo-cross. Apart from cyclo-cross, Nys is also fivefold national mountainbike champion, and has competed in that discipline in two Olympic games.

Cyclo-cross is a form of bicycle racing. Races typically take place in the autumn and winter, and consist of many laps of a short course featuring pavement, wooded trails, grass, steep hills and obstacles requiring the rider to quickly dismount, carry the bike while navigating the obstruction and remount. Races for senior categories are generally between 40 minutes and an hour long, with the distance varying depending on the ground conditions. The sport is strongest in the traditional road cycling countries such as Belgium, France and the Netherlands.