Kastamonu Province is a province of Turkey, in the Black Sea region in the north of the country. It is surrounded by Sinop to the east, Bartın, Karabük to the west, Çankırı to the south, Çorum to the southeast and the Black Sea to the north. Its area is 13,064 km2, and its population is 378,115 (2022). The population density is 29 inhabitants per km2. The provincial capital Kastamonu has a population of 128,707 (2022).

The Black Sea Region is a geographical region of Turkey. The largest city in the region is Samsun. Other big cities are Zonguldak, Trabzon, Ordu, Tokat, Giresun, Rize, Amasya and Sinop.