Old Herzegovina (Serbo-Croatian: Stara Hercegovina, Стара Херцеговина) is a historical region, covering the eastern parts of historical Herzegovina, outside the scope of modern Herzegovina. A large section of Old Herzegovina belongs to modern Montenegro, while a smaller section belongs to the modern Bosnia and Herzegovina and modern Serbia. All of those regions were parts of historical Herzegovina from the middle of the 15th century until 1878.
In modern Montenegro, the region includes the municipal areas of Herceg Novi, Nikšić, Pljevlja, Plužine, Šavnik and Žabljak. In modern Bosnia and Herzegovina, the region includes the municipal areas of Čajniče, Foča, Kalinovik and Rudo. In modern Serbia, the region includes the municipal areas of Priboj and Prijepolje.