Oliva Gessi is a comune (municipality) in the Province of Pavia in the Italian region Lombardy, located about 50 km (31 mi) south of Milan and about 20 km (12 mi) south of Pavia.

[3] Oliva Gessi borders the following municipalities: Calvignano, Casteggio, Corvino San Quirico, Montalto Pavese, Mornico Losana, and Torricella Verzate.

Oliva has been known since 972, when it was donated by Emperor Otto I to his daughter in law Theophano, who then in turn donated it (along with other properties in the nearby villages of Montalto and Mairano near Casteggio) to the monastery of Santa Maria delle Cacce in Pavia.

Passed under the dominion of Pavia (1164), it was included in the podesteria (jurisdiction) of Montalto Pavese and enfeoffed to the family Belcredi.

The domain of the monastery continued, as mere possession of land, under the rule of the feudal lords of Montalto; before the seventeenth century the property was passed to the family Isimbardi of Pavia, vassals of the neighboring Santa Giuletta, who owned the castle and about two-thirds of the lands of the village.