The province has an area of about 9,200 km² (3,551 square miles). It is part of the wider historical region of Epirus, which overlaps modern Albania and Greece but mostly lies in Greek territory.

Greek Epirus, like the region as a whole, is rugged and mountainous.It comprises the land of the ancient Molossians and Thesprotians and a small part of the land of the Chaonians the greater part being in Southern Albania. It is largely made up of mountainous ridges, part of the Dinaric Alps. The periphery's highest spot is on Mount Smolikas, at an altitude of 2.637 metres above sea level. In the east, the Pindus Mountains that form the spine of mainland Greece separate Epirus from Macedonia and Thessaly. Most of Epirus lies on the windward side of the Pindus. The winds from the Ionian Sea offer the region more rainfall than any other part of Greece.