Mediterranean mountains and Pleistocene glacial cycles are responsible for much of the unique biodiversity of the Western Palearctic, acting respectively as refugia and drivers of diversification. Mount Olympus, a legendary Greek landmark, is a perfect example. This massif provided a glacial refugium for many species, resulting in a unique biota. In the present contribution, a new euscorpiid scorpion with a distinctive morphology, Euscorpius olympus, sp. nov., is described from an isolated population in the foothills of Mount Olympus. This new species raises the number of species in the genus Euscorpius Thorell, 1876, to 74, in Greece to 32, and in the vicinity of Mount Olympus, to three. The roles of climatic oscillations, altitudinal gradients and habitat heterogeneity on the diversity and distributions of the three species occurring around Mount Olympus are briefly discussed.