The Italian Peninsula or Apennine Peninsula ( or Penisola appenninica) is one of the three peninsulas of Southern Europe (the other two being the Iberian Peninsula and Balkan Peninsula), spanning 1,000 km from the Po Valley in the north to the central Mediterranean Sea in the south. The peninsula's shape gives it the nickname Lo Stivale (The Boot). Three smaller peninsulas contribute to this characteristic shape, namely Calabria, Salento and Gargano.

Nearly all of the peninsula is part of the state of Italy, apart from San Marino and the Vatican City. Additionally, Sicily and Malta are considered as islands off the peninsula and in this sense geographically grouped along with it.

The peninsula is bordered by the Tyrrhenian Sea on the west, the Ionian Sea on the south, and the Adriatic Sea on the east. The interior part of the Apennine Peninsula consists of the Apennine Mountains, from which it takes its name, the northern part is largely plains and the coasts are lined with cliffs.

This peninsula has mainly a Mediterranean climate, though in the mountainous parts the climate is cooler. Its natural vegetation includes macchia and deciduous and mixed deciduous coniferous forests.