The Delmatae, alternatively Dalmatæ, during the Roman period, were a group of Illyrian tribes in Dalmatia, contemporary southern Croatia and western Bosnia and Herzegovina. The region of Dalmatia takes its name from the tribe.

The Delmatae appear in historical record for the first time in 181 BC, when upon the death of their ruler Pleuratus III of the Illyrian kingdom, they refused to accept the rule of his son, Gentius and seceded. They expanded and came to include coastal Illyrian tribes like the Tariotes, the Hylli and the Nesti and increased their territory to the north against the Liburni. Conflict with Roman expansionism and its local allies in the eastern Adriatic began in 156-55 BC. The Roman–Dalmatae Wars lasted until 33 BC when Octavian (the later Emperor Augustus) installed Roman hegemony in Dalmatia. Local instability and minor rebellions continued in the province of Dalmatia and culminated in the Great Illyrian Revolt in Dalmatia and closely linked Pannonia in 6 AD. The revolt, which lasted for three years, involved more than half a million combatants, auxiliaries and civilians on both side. In the aftermath, some Delmataean communities were relocated in the northern Sandzak region and others were resettled in parts of Carinthia to provide labor for the Roman mines. The defeat of the revolt began the integration of Dalmatia which in turn led to the romanization of the region by the early Middle Ages.