Lusitania or Hispania Lusitania is an ancient Iberian Roman province including approximately all of modern Portugal south of the Douro river and part of modern Spain (the present autonomous community of Extremadura and a small part of the province of Salamanca).

It is named after the Lusitani or Lusitanian people (an Indo-European people).

Its capital is Emerita Augusta (currently Mérida, Spain), and it is initially part of the Roman Republic province of Hispania Ulterior, before becoming a province of its own in the Roman Empire.

Romans first come to the territory around the mid 2nd century BCE.

A war with Lusitanian tribes follows, from 155 to 139 BCE In 27 BCE, the province was created.