Lorenzo Demetrio Zanetti (born August 10, 1987) is an Italian motorcycle racer. In 2015 he competes in the Supersport World Championship for MV Agusta Reparto Corse aboard a MV Agusta F3 675.
Born in Brescia, Zanetti finished second behind Luca Di Giuseppe in the Honda RS125 GP Trophy in 2003 and won the title the following year. In the same seasons he competed in the Italian 125 GP Championship and in 2004 he made his debut in the 125cc World Championship; he raced in the latter series until the end of 2009. In 2010 he was second in the Italian Stock 600 Championship and debuted in the Superstock 1000 FIM Cup, which he finished in third position in 2011. For 2012 he moved to the Superbike World Championship and then in 2013 to the Supersport World Championship. On July 21, 2013 during the race held in Moscow he was involved in the accident which resulted in the death of Andrea Antonelli. He continued to race in the same championship for 2014 and 2015.