Olivetta San Michele (Royasc: , also ) is a comune (municipality) in the Province of Imperia in the Italian region Liguria, located about southwest of Genoa and about west of Imperia, on the border with France. As of 31 December 2004, it had a population of 245 and an area of .
Olivetta San Michele borders the following municipalities: Airole, Breil-sur-Roya (France), Castellar (France), and Ventimiglia.