Charly Grosskost (5 March 1944 – 19 June 2004) was a French racing cyclist who, in 1968, won the prologue time trial of both the Giro d'Italia and the Tour de France. He won stages of the Tour de France and the Giro d'Italia, and on the track, he was French pursuit champion nine times. His sporting career began with A.C.B.B. Paris.^[2]

Grosskost came to notice when he was 19, when he won a stage of the Route de France – amateur counterpart of the Tour de France – and then won Strasbourg-Campagne by nearly 10 minutes after riding ahead of the race for more than 50 km. In 1965, he won the Route de France and five of its seven stages and became favourite for the still bigger race, the Tour de l'Avenir. There, however, he dropped out in the Pyrenees. A drug test that followed his retirement – it has entered cycling legend that other riders pushed him off his bike for his own safety as he began foaming at the mouth and riding erratically – led to his being suspended for a year. To his death, Grosskost insisted that he had been drugged by a team helper.

Grosskost turned professional for Peugeot on 1 May 1966, alongside Eddy Merckx of Belgium, whom he beat to win his Giro prologue. He then moved to the Bic team alongside Jacques Anquetil.

In 1968 he won the prologue of the Giro d'Italia and became the third Frenchman to wear the leader's pink jersey after Louison Bobet and Raphaël Géminiani. That same year, Grosskost won the prologue time-trial of the Tour de France at Vittel and then the first conventional stage. He wore the leader's yellow jersey for three days and finished the Tour in 17th place.

In retirement he became a cycle dealer.

Grosskost died in 2004, after he was hit by a car while cycling with friends.^[3]

• List of doping cases in cycling