The wild olive is a cornerstone of Mediterranean ecosystems and a wild relative of the cultivated olive. We wanted to know how a warming climate might reshape where it can grow. Using records of where the tree grows today together with climate data, we mapped its suitable habitat now and in the future. Suitable areas shrink under every future scenario we tested and shift northward, with the sharpest losses late this century, making cuts to greenhouse gas emissions important for the wild olive's survival.