Kozcağız is a town and municipality located in the Bartın District of the Bartın Province in Turkey. It is situated on the west bank of the Kocanaz creek, positioned approximately 20 kilometres (12 miles) from the city of Bartın.
As of 2021, the population of Kozcağız is recorded at 7,248 residents. The area serves as a local municipality within the regional administrative structure of the province.