The Campaccio is an annual cross country running competition which takes place in early January in San Giorgio su Legnano, Italy. Organised by the Unione Sportiva Sangiorgese, the event attracts participation from Olympic and world champions in athletics, in spite of the fact that the host town has a population of just over 6000. It is typically the first major athletics event of the year in Italy, and holds IAAF Cross Country Permit status.

San Giorgio su Legnano is a comune (municipality) in the Metropolitan City of Milan in the Italian region Lombardy, located about 20 kilometres (12 mi) northwest of Milan.