Postojna is a town in the traditional region of Inner Carniola, 35 kilometers (22 mi) from Trieste, in southwestern Slovenia. It is the seat of the Municipality of Postojna. It includes the hamlet of Ravbarkomanda to the northeast.

The Municipality of Postojna is a municipality in the traditional region of Inner Carniola in southwestern Slovenia. The seat of the municipality is the town of Postojna. The municipality was established in its current form on 3 October 1994, when the former larger Municipality of Postojna was subdivided into the municipalities of Pivka and Postojna.