Kassandreia, known as Valta before 1955, is a town and a community in Chalkidiki, northern Greece. It is the seat of the municipality of Kassandra, in the center of the peninsula. Its population was 3,158 at the 2021 census. It was named after the ancient city Cassandreia, which was located near the village. This ancient city, which had originally been called Potidaea, was enlarged by Cassander who became the ruler of Macedonia for a number of years, and named after him.