Over the last years, there has been tremendous debate regarding the identity of feta cheese and under which terms such food with historical ties to ancient Greece can be discriminated among others, based on its unique traits and characteristics. This analysis sets the foundation towards a much anticipated control procedure, by deciphering for the first time the core elements of this food; its proteins. In this initial report, we amassed representative feta cheese samples/types from parts of Greece entitled to produce this "protected designation of origin" (p.d.o) cheese type and analyzed in full their protein content by employing exhaustive deep-proteome analyses. Several groups of proteins were identified, implicated in diverse functions as well as proteins under multiple abundances, while the final feta cheese protein list was set to include solely core-proteins identified in every analyzed sample. Through this data article we report, for the first time, the complete protein content of feta cheese, consisting of 489 proteins, thus setting the foundation towards developing a method for identification of the original Greek product.