Ithaca or Ithaki is a Greek island located in the Ionian Sea, off the northeast coast of Kefalonia and to the west of continental Greece. It is the second-smallest of seven main Ionian Islands, after Paxi. The capital is Vathy (or Vathi).

Modern Ithaca is generally identified with Homer's Ithaca, the home of Odysseus, whose delayed return to the island is the Odyssey's plot.