The olive tree is of strategic importance for the Mediterranean basin, and olive oil is an important component of Mediterranean diet, with beneficial properties for human health. The longevity of this species and the low breeding pressure have largely determined the genetic diversity that exists in the olive tree. Today, olive resources are represented by very wide germplasm estimated in more than 1.700 cultivars. This chapter is a report on the synthesis of what is known about the botanical and historical origin of olive tree. Furthermore, the morphological and genetic methodologies used to identify olive cultivar are examined
