Vlasis is a village in Messene Municipality, in the regional unit of Messenia, in the region of Peloponnese, Greece. Vlasis lies at 399 m above sea level, 1.2 km from the Peloponnese mountains. It has 112 inhabitants (2021). The nearest city is Kalamata, 27 km to the east. Beaches nearby: Gialova (14 km), Gialova (15 km). Among the landmarks around are Messene (16.9 km), Palace of Nestor (10.5 km) and Ithome (18.4 km). Among the natural features are Polylimnio waterfalls (8.1 km).

Also written Βλάσης.