Karahisar ("black castle" in Turkish) may refer to the following places in Turkey:
Afyonkarahisar, a city in Afyon Province (formerly known as Karahisar-i Sahip, Afium-Kara-hissar, Afyon Karahisar) Şebinkarahisar, a district center in Giresun Province (formerly known as Kara Hisar-ı Şarkî, Şarkî Kara Hisar, Şapkarahisar) Karahisar, a town in Tavas district of Denizli Province Karahisar, Çorum Karahisar, Keşan