Dutch cyclist Jan Janssen was born on the 19th of May 1940 in Nootdorp, a suburb of Delft, Holland. Janssen is notable for his victory in the Tour de France in 1968, beating Herman Van Springel and Ferdinand Bracke of Belgium. This victory was only a slight improvement on his 1966 achievement, when he came second to Lucien Aimar of France.

As a young boy, Janssen worked alongside his father and brother in the construction industry, convinced of his own value as a cyclist but unable to satisfactorily convince his parents. Despite their misgivings, Janssen began a 28 year racing career at the age of 15. By 1963 he had won nearly fifty races, including three stages of the '62 Tour de l'Avenir, at which point he made the decision toturn professional and sign with the Pelforth Sauvage team. The Tour de l'Avenir was the opportunity for Janssen to show his talent as an all-round cyclist.

Stage victories in 1964 were followed by victories in Paris-Nice and the World Championships, and led to his eventual success in the Tour de France. Despite not wearing the yellow jersey (maillot jaune) at all throughout the race and with a lag of sixteen seconds behind the leader, Herman Van Springel, Janssen pushed through to win the overall race by thirty-eight seconds, making him the first Dutchman to win the Tour. This time was the smallest margin for a Tour win until 1989 when Greg LeMond beat Laurent Fignon by a mere eight seconds.

Janssen was awarded the title Dutch Sportsman Of The Year in 1968, the same year that Ada Kok achieved Sportswoman Of The Year for her swimming achievements.