The Ionian Sea is an arm of the Mediterranean Sea, south of the Adriatic Sea. It is bounded by southern Italy, including Calabria and Sicily, to the west, by southwestern Albania and a large number of Greek islands, including Corfu, Zante, Kephalonia, Ithaka, and Lefkas to the east. The islands are collectively referred to as the Ionian Islands, and other islands including the Strophades , Sphagia, Schiza , Sapientza and Kythira. The sea is one of the most seismic areas in the world.

The ferry route between Patras and Brindisi and Ancona crosses over the east and north and shipping routes from Athens westward cross over the Ionian.

Other ferry routes connecting the islands and land except for Lefkada are mainly in the east and southeast

Places

In order from south to north in the west and then north to south in the east:

• Syracuse, port, W
• Catania, port, W
• Saranda, port and a beach, NE
• Parga, small port
• Astakos
• Fiskardo , no port
• Keri , no port
• Methoni , small port and a beach

Gulfs and straits

• Strait of Messina, W
• Gulf of Taranto, NW
• Ambracian Gulf , E
• Gulf of Patras, connecting the Gulf of Corinth, ESE
• Cyparissian Gulf , SE
• Messenian Gulf , SE
• Laconian Gulf , ESE

Tributaries

In order from north to south

• • Peneus River (Peloponnese)
  • Ambracian Gulf
    • Acherontas River
  • Gulf of Patras/Strait of Rio-Antirrio Watershed
    • Achelous River
    • Glaucos/Glavkos River - Panachaicus mountains to south of Patras
    • Louros River , north
  • Cyparissian Gulf
    • Alpheus River
      • Kladeos or Cladeus River
      • Erymanthus River
        • Ladon River
        • Ladon Lake
    • Loussios River
    • Larissos River - Nea Manolada
    • Neda River - Elia-Messenia boundary/border