Preveza is a city in the region of Epirus, northwestern Greece, located on the northern peninsula of the mouth of the Ambracian Gulf. It is the capital of the regional unit of Preveza, which is the southern part of the region of Epirus. The Aktio-Preveza Immersed Tunnel –the first and so far only undersea tunnel in Greece– was completed in 2002. The 1,570 m long immersed tunnel connects Preveza in the north, to Aktio of western Acarnania to the south. The ruins of the ancient city of Nicopolis lie 7 kilometres north of Preveza.

Epirus is a traditional geographic and modern administrative region in northwestern Greece. It borders the regions of Western Macedonia and Thessaly to the east, West Greece to the south, the Ionian Sea and Ionian Islands to the west and Albania to the north. The region has an area of about 9,200 km2 (3,600 sq mi). It is part of the wider historical region of Epirus, which overlaps modern Albania and Greece but lies mostly within Greek territory.