Magna Graecia (Latin for "Greater Greece," Megalê Hellas/Μεγάλη Ελλάς in Greek) is the name of an area in ancient southern Italy and Sicily that was colonised by ancient Greek settlers in the 8th century BCE.

Originally, Magna Graecia was the name used by the Romans to describe the greater area around the ancient Greek colony of Graia (Γραία), and the whole area of Greek colonisation became known by this name. The modern-day terms of "Greece" and "Greeks" in English and many other languages stem from the Roman "Magna Graecia"; the Greeks rather call themselves Hellenes and their country Hellas.

With this colonisation, the Greek culture was exported to Italy, and soon developed an original civilisation, later interacting with the native Italic and Latin civilisations.

Many of the new cities become very powerful and rich, like Kapuê (Capua), Neapolis (Νεάπολις, Naples), Subaris (Σύβαρις, Sybaris).

Other cities in Magna Graecia included Syrakousses (Συρακούσσες, Syracuse), Akragas (Άκραγας, Agrigento), Taras (Τάρας, Taranto), Lakroi or Locri (Λοκροί), Rhegion (Ρήγιον), Kroton (Κρότων, Crotone), Thurii (Θούριοι) and Elea (Ελαία).

A small Griko-speaking minority still exists today in Calabria and mostly in Salento. Griko is the name of a language combining ancient Greek, Byzantine Greek and Italian elements, spoken by people in the Magna Graecia region. There is rich oral tradition and Griko folklore.