Corfu ( , Kérkyra, IPA2: ˈkʲe̞ɾkʲiɾa; ; ; ) is a Greek island in the Ionian Sea. It is the second largest of the Ionian islands, and lies off the coast of Sarandë, Albania, from which it is separated by straits varying in breadth from 3 to 23 km (2 to 15 mi), including one near ancient Butrint and a longer one west of Thesprotia. The island is part of the Corfu Prefecture, and includes twelve of the sixteen municipalities or communes in the prefecture and over Communities of Ereikoussa, Mathraki, Othonoi, and Municipality of Paxoi, which are all separate islands.

The principal town (pop. 28,185) of the island is also named Corfu, or Kérkyra in Greek, as is its municipality (pop. 39,487). Corfu is home to the Ionian University.

The island is steeped in history and perennially connected to the history of Greece from the beginning of Greek mythology. Its Greek name, Kerkyra or Korkyra, is connected to two powerful water symbols: Poseidon, god of the sea and Asopos, an important Greek mainland river.Greek Mythology Encyclopedia According to myth, Poseidon fell in love with the beautiful nymph Korkyra, daughter of Asopus and river nymph Metope, and abducted her, as was the custom among gods of the era's myths – Zeus himself was a serial offender. Poseidon brought her to the hitherto unnamed island and, in marital bliss, offered her name to the place: Korkyra, which gradually evolved to Kerkyra (Doric). Together, they had a child they called Phaiax, after whom the inhabitants of the island were named: Phaiakes, which was then transliterated via Latin to Phaeacians. The island's history is laden with battles and conquests, indicative of Corfu's turbulent position in a historical vortex lasting until the modern period, at which time unification with modern Greece from 1864 made the island's history one with that of the mainland, with no further foreign intervention. The legacy of these struggles is visible in the form of castles punctuating strategic locations across the island. Two of these castles enclose its capital, which is the only city in Greece to be surrounded in such a way. As a result, Corfu's capital has been officially declared a Kastropolis (Castle city) by the Greek Government. In 2007, the city's old town was named on the UNESCO World Heritage List, following a recommendation by ICOMOS.UNESCO Advisory Body (ICOMOS) report on Corfu History retrieved 3 July 2007Old Town of Corfu on UNESCO website retrieved 3 July 2007