The domesticated olives originated based on decades of selection from the natural forest around the Mediterranean basin being one of the oldest cultivated tree crops. The requirement for new olive varieties increased markedly during the last 100 years as a result of a worldwide transformation changing from a traditional extensive to a modern intensive mechanized industry. The traditional olive cultivars still widely used are selections from the local autochthonous cultivars which are well adapted to their natural environment. However, the level of production of those is usually rather low and many of them failed to respond enough to modern intensification methods. The wild olive population is gradually diminishing in all regions thus, natural selection is not efficient enough for developing the cultivars required for the new intensive olive industry. Cross breeding between cultivars with specific characters became the basis for the required new cultivars. The genetic diversity in progenies of most olive cultivars is extremely wide and thus becomes the basic source for breeding of the needed new cultivars. However, the genetic information on olive heredity and identification of specific gene characteristics is still limited. Genomic information is required for rational choice of genitors in accordance with each breeding aim, particularly as most criteria required for the new varieties are of multi-gene nature. The availability of advanced genomic information will also serve as basis for molecular engineering when accepted for use in the olive commodity. Geographically isolated olive populations developed during generations of inbreeding in remote regions are another important genetic resource of characters required for breeding the cultivars for the new modern mechanized olive orchards. The use of molecular markers based on AFLP, SSRs, DArT and SNPs is important for the choice of genitors leading to a reduction of the progeny size required in olive breeding. Presently the newly released olive cultivars are still the result of classical breeding.