The Classical and Celtic world had a long history of economical and social interaction prior to the first century b.C. Although the influence of the Classical world in the Celtic material culture remains undisputed by archaeologists and historians, there are few studies proposing to view this influence in other aspects of the Celtic societies such as in the ideas and social organization before the Roman conquest. The present study proposes to investigate one of these aspects by analyzing two of the better known Celtic Priesthoods druids and vates as portrayed by the Classical authors during the 1st Century BC in relation to the functions and organization of the priests of Rome, exposing their similarities and differences while providing a critical model through which they might be better understood.