Stefano Manzi (born 29 March 1999) is an Italian motorcycle racer.
Born in Rimini, from 2012 to 2014 Manzi was a competitor of the Red Bull MotoGP Rookies Cup, where he finished third in 2013 and 2014. The following year he made his debut in the Moto3 World Championship, racing from the second round of the season onwards—after being replaced for the opening event by Marco Bezzecchi due to age limits on a Mahindra MGP3O entered by San Carlo Team Italia alongside his compatriot Matteo Ferrari. Of his four point-scoring finishes, his best result was a twelfth place in Aragon. In 2016 he appeared in the same class as a wild card at selected rounds, scoring a fourth place at Silverstone.
In 2017, Manzi moved to the Moto2 class with Sky Racing Team VR46 alongside fellow Italian Francesco Bagnaia riding a Kalex, Manzi best results was 7th at Silverstone.
For 2018, Manzi switched to Forward Racing, swapping places with Luca Marini who went to Sky Racing Team VR46.