Phocaea, or Phokaia (modern-day Foça in Turkey), is an ancient Ionian Greek city on the western coast of Anatolia.

Greek colonists from Phocaea establish the colony of Massalia (modern day Marseille, in France) in 600 BCE, Emporion (modern day Empúries, in Catalonia, Spain) in 575 BCE and Elea (modern day Velia, in Campania, Italy) in 540 BCE.The ancient Greek geographer Pausanias says that Phocaea was founded by Phocians under Athenian leadership, on land given to them by the Aeolian Cymaeans, and that they were admitted into the Ionian League after accepting as kings the line of Codrus.

Pottery remains indicate Aeolian presence as late as the 9th century BCE, and Ionian presence as early as the end of the 9th century BCE.

From this an approximate date of settlement for Phocaea can be inferred.

According to Herodotus the Phocaeans were the first Greeks to make long sea-voyages, having discovered the coasts of the Adriatic, Tyrrhenia and Spain.

Herodotus relates that they so impressed Arganthonios, king of Tartessus in Spain, that he invited them to settle there, and, when they declined, gave them a great sum of money to build a wall around their city.

Their sea travel is extensive.

To the south they probably conduct trade with the Greek colony of Naucratis in Egypt, which is the colony of their fellow Ionian city Miletus.

To the north, they probably help settle Amisos (Samsun) on the Black Sea, and Lampsacus at the north end of the Hellespont (now the Dardanelles).

However, Phocaea's major colonies are to the west.

These included Alalia in Corsica, Emporiae and Rhoda in Spain, and especially Massalia (Marseille) in France.