The Cephalonia Prefecture (Greek: Νομός Κεφαλληνίας) was a prefecture in Greece, containing the Ionian islands of Cephalonia and Ithaca. In 2011 the prefectural self-government was abolished and the territory is now covered by the regional units of Cephalonia and Ithaca.

It was previously divided into 3 eparchies (provinces), and one independent municipality, Ithaca:

The prefecture was divided into eight municipalities and one community:

All of the preceding are on the Cephalonia island, except Ithaca, which is on its own island of the same name.

38°15′N 20°30′E / 38.25°N 20.5°E / 38.25; 20.5