Kefalonia or Cephalonia, formerly also known as Kefallinia or Kephallenia (Κεφαλληνία), is the largest of the Ionian Islands in western Greece and the 6th largest island in Greece after Crete, Euboea, Lesbos, Rhodes and Chios. It is also a separate regional unit of the Ionian Islands region. It was a former Latin Catholic diocese Kefalonia–Zakynthos (Cefalonia–Zante) and short-lived titular see as just Kefalonia. The capital city of Cephalonia is Argostoli.

Ithaca was, in Greek mythology, the island home of the hero Odysseus. The specific location of the island, as it was described in Homer's Odyssey, is a matter for debate. There have been various theories about its location. Modern Ithaca has traditionally been accepted to be Homer's island. One recent alternative candidate is Paliki, which may have been an island separated from the rest of Kefalonia, as argued by Bittlestone, Diggle and Underhill in Odysseus Unbound. This theory, however, has not been generally accepted on grounds of geology, archaeology, philology, or historical and Homeric analysis. “What is clearly missing,” wrote Dr Christine Haywood reviewing Odysseus Unbound, “is a good knowledge of the complexities of Homeric language, and the support of archaeology.”