Marmilla is a natural region of southern-central Sardinia, Italy.
It is delimited from east and south by the Campidano, from north-west by Monte Arci, from north by the Giara di Gesturi and the Giara di Serri, and from east by the Flumini Mannu.
Geologically, most of Marmilla dates to the Miocene period, and is thus substantially younger than the rest of Sardinia. The landscape is mostly hilly, and human economical activities in the area include agriculture (prevalently cereals and fava beans) and tourism.
Marmilla was inhabited since prehistoric times, as testified by the presence of nuraghe. To the Carthaginian domination date the fortress of Genoni. During the Middle Ages it was part of the Giudicato of Arborea and of the Giudicato of Cagliari.
Coordinates: 39°42′00″N 8°47′00″E / 39.7000°N 8.7833°E