Dalmatia (Croatian: Dalmacija, Croatian pronunciation: [dǎlmaːt͡sija]; see names in other languages) is a historical region on the eastern coast of the Adriatic Sea, in Croatia. It stretches from the island of Rab in the northwest to the Bay of Kotor in the southeast. The hinterland, the Dalmatian Zagora, ranges from fifty kilometers in width in the north to just a few kilometers in the south. The Dalmatian dog received its name from Dalmatia, as does the dalmatic, a Roman Catholic liturgical vestment worn by deacons and bishops.

The name Dalmatia derives from the name of the tribe of the Dalmatae, which is connected with the Illyrian word delme, dele in modern Albanian, meaning "sheep" in English.

In antiquity the Roman province of Dalmatia was much larger than the present-day Dalmatia County of Croatia, stretching from Istria in the north to historical Albania in the south. Dalmatia signified not only a geographical unit, but was an entity based on common culture and settlement types, a common narrow eastern Adriatic coastal belt, Mediterranean climate, sclerophyllous vegetation of the Illyrian province, Adriatic carbonate platform, and karst geomorphology.