Petalidi is a village and a former municipality in Messenia, Peloponnese, Greece. Since the 2011 local government reform it is part of the municipality Messini, of which it is a municipal unit. The municipal unit has an area of 104.970 km2. Petalidi is situated on the western shore of the Messenian Gulf, 14 km southwest of Messini, 20 km southwest of Kalamata and 25 km east of Pylos. The road Greek National Road 82 passes through the north of the municipal unit. Its population is 1,203 inhabitants, while the municipal unit has 2,555 residents (2021).