Marla Streb (born 24 June 1965) is an American professional mountain bike racer. She rides for the professional trade team Luna Women's Professional MTB Team and Red Bull. Streb is most known for racing downhill, however, she does race XC. She has twice won the Single Speed World Championship, in 1999 and 2005. She has also written two books, has been featured on network television and movies, and is working on creating mountain bike parks in Costa Rica.