Ithaca is an island of Eptanisa lying south of Lefkada and east of the northwest coast of Kefalonia, from which it is separated by the Strait of Ithaca. Its capital is Vathi. Ithaca is an oblong shaped island covering an area of 96 square kilometers (37 sq mi). Its population is 3.231 according to the 2011 census. Since 2011, as a part of the Kallikratis government reform, Ithaca has been a separate Regional Unit. No changes have been made to the Ithaca Municipality. Ithaca belongs administratively to the Ionian Islands Prefecture.

Ithaca has 2 ports, Vathi and Piso Aetos, both being connected with Patras via Sami (port of Kefalonia). Piso Aetos is also connected with Fiskardo (Kefalonia), Vasiliki (Lefkada) and Astakos (Aitoloakarnania). Ships also connect Frikes with Fiskardo and Vasiliki or Nydri.

The island is divided into the former Ithaca Municipality (Vathi) and seven municipal districts, highland and seaside. Vathi is a picturesque town with a peculiar bay that embraces the Lazareto islet and its two venetian castles. During the summer high season the population of the island doubles.

Ithaca owes its name to Ithacus, the first inhabitant of the island (son of Pterelaos and brother of Polyktor and Niritos) or -according to mythology- son of Poseidon and Amfimeli. According to another version, the name is derived from the word ‘Ithi’ (=cheerful) or from the Phoenician word ‘Utika’ (=colony) or from the word ‘Ithys’ (=abrupt).

Vathi and the local districts of Anogi, Stavros and Kioni have been designated as traditional settlements, while the whole island is considered of exceptional natural beauty.

Ithaca’s eastern coastline is rich with many bays and capes. The northern end point of the island is Melissa cape, while the southern is Agios Andreas cape. Between these two ends, Frikon cove, Mavronas cape, Agios Ilias cape, Molos bay, Sxoinos cape and several other capes intervene. The coastline extends to a length of 101 km. The island also features Nirito (806 m) and Merovigli (669 m) mountains.

The island is characterized by infertile lands and water scarcity; factors that obstruct the agricultural growth. Ithaca mainly relies economically on tourism and fishing. The island’s name is known since the ancient times as it is mentioned in Odyssey. Modern scholars generally accept the identification of modern Ithaca with Homeric Ithaca, and explain discrepancies between the Odyssey's description and the actual topography as a result of lack of first-hand knowledge of the island, or as poetic license.