Sven Nys (Dutch: [sfɛˈnɛis]; born 17 June 1976) 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.