Thelma Bishop from Gatley in Stockport bought the ceramic jug for a few dollars while on holiday in the 1960s.
Its history was discovered by auctioneers after Ms Bishop decided to sell it.
She was told she could have been prosecuted for removing it. Turkish officials are said to be "delighted".
Ceramics expert Jason Wood at Adam Partridge Auctioneers said: "It is being returned to the Turkish authorities because it would have exposed the owner to legal proceedings if (Ms Bishop) had gone ahead and made a sale.
"That is because when she took it out of the country, inadvertently it was breaking a Turkish law which dates back to the 1880s.
"It is an early bronze age ceramic vessel, made specifically to be a grave good, so it was buried in cemeteries. (It was) commonly found in Western Anatolia in Turkey."
Mr Wood said the item was "fairly rare".
He said: "Its archaeological value is why it is important. There are a few examples; there is one in the British Museum, one in the Metropolitan Museum in New York and they crop up periodically, a few in Turkey as well, but to have one turn up in Stockport of all places and in such remarkable condition is quite unusual."
Ms Bishop has been offered a free museum pass in Istanbul for returning the jug to the Turkish authorities who are said to be "delighted".
The ceramic vessel will go on display at The Museum of Anatolian Civilizations in Ankara.
A woman who bought a souvenir jug in Turkey more than 50 years ago is to return it after discovering it is a bronze-age urn.