Demirköy District is a district of the Kırklareli Province of Turkey.

Its seat is the town of Demirköy at the Istranca/Yildiz Mountains at the foot of the Mahya Dağı.

[1] Its area is 893 km2,[2] and its population is 8,961 (2022).

[3] The population of different background merged, and are now called simple Hill people (Dağlılar).