Studies of the species composition, seasonal appearance, and abundance of Auchenorrhyncha in olive crops is of paramount importance to reduce the potential of Xylella fastidiosa to invade new areas. As similar investigations had not previously been conducted in Greece, extensive surveys were undertaken in olive orchards located in three of the most important regions for olive production in central Greece (Fthiotida), south-central Greece (Attica), and southern Greece (Chania). Surveys took place over a 13-mo period, using Malaise traps examined on a monthly basis. Results showed high levels of species richness in the olive orchards, and the Auchenorrhyncha diversity varied among the regions surveyed. Most of the species listed as potential vectors of X. fastidiosa in Europe were found in relatively low numbers. Furthermore, many insects of the Deltocephalinae subfamily were found, whose behavior as vectors should be further studied. The dominant and most frequent species found in the three regions were tested and found not to be associated with transmission of the bacterium. This study may serve as an alert, showing that the most commonly found species differ from those identified in similar studies in Italy, and thus other species should be examined as potential vectors. The results of the present study provide new insights into the seasonal abundance and dynamics of potential vectors of X. fastidosa in several regions of Greece, and also provide information that may prove valuable for the effective containment and eradication of this threat.