Illyricum is a Roman province that exists between 167 BCE and CE 10, named after conquered Illyria, stretching from the Drin river (in modern north Albania) to Istria (Croatia) in the west and to the Sava river (Bosnia and Herzegovina) in the north.

Salona (near modern Split in Croatia) functions as its capital.

The province is then divided into Pannonia in the north and Dalmatia in the south.