This work presents, for the first time, an overview of the rich geodiversity outcropping in the S？o Tomé island, one of the two islands that make up the archipelago of S？o Tomé and Príncipe, the second smallest state of Africa in area. Located at the equator, in the alignment known as the “Cameroon Volcanic Line”, this archipelago represents a privileged area for the comparative study between oceanic and continental alkaline volcanism, and therefore between the subcontinental and suboceanic mantle. Ten geosites of S？o Tomé island were selected, described and evaluated on the basis of their geoheritage value and using a qualitative system of classification, which integrates both the meaning attributed to the objects by scientific communities and the public understanding of such meanings related to its social use. The selected geosites display different heritage values (documental, scenic, symbolic, iconographic and indicial) potentially usable for different purposes, namely scientific and educational, but mostly tourism. Geotourism can play a key role in the promotion of sustainable development in the Democratic Republic of S？o Tomé and Príncipe, and the geosites here described are likely to ground a geo-itinerary on this “pearl” of the Cameron Line.