Nanos (pronounced [ˈnaːnɔs]; Italian: Monte Re) is a karst limestone plateau at the eastern border of the Inner Carniola in southwestern Slovenia.

In the 1st century, the pass at Nanos was an important route for civilian and military traffic from Trieste (Tergeste) to Ljubljana (Emona) and beyond to Carnuntum at the Danube.

[5] Nanos is mentioned as Nanas in Johann Weikhard von Valvasor's 1689 work The Glory of the Duchy of Carniola.

It was one of the first battles between the Partisan insurgence in the Slovene Littoral, led by Janko Premrl, and the Italian Army, and was the beginning of the struggle for the western border between the two nations.

[8] Their most highly valued product is the Nanos cheese, produced already in the 16th century and, since October 2011, the protected designation of origin label.