Eleios-Pronnoi is a former municipality on the island of Kefalonia, Ionian Islands, Greece. Since the 2019 local government reform it is part of the municipality Argostoli, of which it is a municipal unit. The municipal unit has an area of 111.687 km2. The seat of the municipality was in Pastra. The municipal unit contains several mountain ranges, including the eastern part of Mount Ainos.