The artefact, called the “Fagan Fragment”, has been on display at the Antonino Salinas Museum in Palermo.
The Fagan Fragment derives its name from Robert Fagan, a former British consul for Sicily and Malta.
The fragment depicts the feet of the goddess Artemis, draped under a tunic.
It was taken from the eastern frieze of the Parthenon, which forms an image of the Olympian gods sitting and watching the delivery of a veil to Athena.
The fragment will be on display at Athens’ Acropolis Museum for eight years.
In return, the Acropolis Museum has loaned Sicily a headless statue of Athena from the 5th century BC and an amphora from the 8th century BC.
The return of the Fagan Fragment to Greece has sparked renewed calls for the British museum in London to follow suit, as it houses one of the largest collections of Greek antiquities – which includes the Elgin Marbles – in the world.