Apollonioi is a former municipality on the island of Lefkada, Ionian Islands, Greece. Since the 2011 local government reform it is part of the municipality Lefkada, of which it is a municipal unit. It is located in the southwestern part of the island. Its population was 2,389 at the 2021 census. The seat of the municipality was in Vasiliki. Its area is 124.709 km2, comprising about 41 percent of Lefkada Island. The area features beautiful beaches on the western side of the island, the most famous are in Porto Katsiki and in Ekremnoi. The Porto Katsiki Beach has been voted the second best beach in the world.