Diego Alessi (born 3 November 1971 in Rome) is an Italian race car driver.

He competed in the Italian Touring Car Championship from 1996–1999 and 2001–2002 - obtaining 12 poles and 12 wins - then moved to the Trofeo Maserati Europe - with 19 poles and 3 wins between 2003 and 2006 - as well as making 3 starts in FIA GT for Autorlando Porsche.

From 2006 to 2010 Diego Alessi competed in FIA GT3 Championship at the wheel of Maserati Grand Sport, Aston Martin DBRS9, Corvette Z06 and Ferrari 430 Scuderia, obtaining 1 pole, 2 wins and the 3 rd final overall place on 2007 championship.

In 2008, Diego participated in the Rolex Sports Car Series, driving a Pontiac GTO.R with young Californian Ryan Phinny, for Matt Connolly Motorsports P1 Groupe.

Team drove in the 24 Hours of Daytona with Hal Prewitt, Karl Reindler, Vic Rice and Spencer Trenery.