Gytheio or Gythio, also the ancient Gythium or Gytheion, is a town on the eastern shore of the Mani Peninsula, and a former municipality in Laconia, Peloponnese, Greece. Since the 2011 local government reform it is part of the municipality East Mani, of which it is a municipal unit. The municipal unit has an area of 197.313 km2. Gytheio was the seaport of Ancient Sparta, which lies approximately 40 kilometres north of it.