Ajdovščina (pronounced [ˈaːi̯dɔu̯ʃtʃina] ⓘ; Italian: Aidussina,[3] German: Haidenschaft[4]) is a town in the Vipava Valley (Vipavska dolina), Slovenia.

In the early period of the Roman Empire, after a road was built from Aquileia towards Emona, a small post and goods station known as mansio Fluvio Frigido stood on the site of today's Ajdovščina.

Thus the population adopted and modified the classical Karst architecture for their own needs; for example, by putting stones on roofs to weight down the tiles against the strong winds.

The town is located around 25 km from the Adriatic Sea.The parish church in Ajdovščina is dedicated to John the Baptist and belongs to the Diocese of Koper.

The church in the hamlet of Fužine north of the main town, dedicated to Saint Anthony of Padua, also belongs to this parish.