- an ancient region of varying extent in the E part of the Balkan Peninsula: later a Roman province; now in Bulgaria, Turkey, and Greece.
- a modern region corresponding to the S part of the Roman province: now divided between Greece (Western Thrace ) and Turkey (Eastern Thrace ).
- an ancient country in the E Balkan Peninsula: successively under the Persians, Macedonians, and Romans
- a region of SE Europe, corresponding to the S part of the ancient country: divided by the Maritsa River into Western Thrace (Greece) and Eastern Thrace (Turkey)
