Marc Janssens (born 13 November 1968 in Duffel) is a Belgian former cyclo-cross cyclist.

Professional from 1993 to 2001, he won the Belgian national cyclo-cross championship three times. He also won the Gazet van Antwerpen Trophy twice, placed third in the World Cup twice, and finished second in the 1996 Superprestige. After his racing career, he became a commentator of cyclo-cross competitions on the Flemish TV channel VT4. He is also currently a directeur sportif for the ERA team.