Wave energy represents the ‘new entry’ to Renewable Energy Sources discussion, in the context of clean and sustainable energy solutions in the electricity production sector. This research describes a geo-spatial Multiple-Criteria Decision Analysis, based on the Geographic Information Systems technology, for the identification of the best location to deploy a potential Wave Energy Farm in the Ionian Sea, an area offshore the Greek mainland West coast. For this purpose, several factors are taken into consideration; restrictions such as protected areas, military exercise areas etc. and weighted factors such as distance to power grid, wave height etc. The wave resource assessment is completed through real data measurements and numerical wave model approximations. The results pinpoint the most suitable areas for installing the proposed wave power plants, i.e. near the SW coast of Corfu, in the West side of the Straits between Kefallonia and Zakynthos and near the broader area of Pylos, in the SW coast of Peloponnesus. The suggested methodology can be equally applied in other spatial planning cases too, being considered as a checklist, addressed to policy-makers and private investors.