Marc Madiot (born 16 April 1959) is a French former professional road racing cyclist and double winner of Paris–Roubaix. He also competed in the individual road race event at the 1980 Summer Olympics. Retired from racing in 1994, he is now best known as the directeur sportif of Groupama–FDJ United, a UCI WorldTeam. He is also known as the president of the French Ligue National de Cyclisme (LNC). In 1987, he made disparaging remarks about the sport of women's cycling, calling it ugly and unesthetic.

In 2008, he was made a knight of the French Legion of Honor. It was presented by president Nicolas Sarkozy at the Elysée palace in Paris.

He is the older brother of fellow retired racing cyclist and French national road racing champion Yvon Madiot.