Olea europaea Olive
There's no problem in finding Olive trees on Crete but the question is whether any, even those in the obviously wild countryside were actually wild and native or not. My guess is that since Olives have been grown for centuries, all the trees we saw are derived from cultivars but this was was certainly in a wild spot so it is the nearest thing to wild Olive we found.
Olea europaea is native to the eastern Mediterranean but is now grown throughout for Olive Oil.