Pepuza (also spelled Pepouza) was an ancient town in Phrygia, Asia Minor (in today's Turkish district of Karahallı, Province of Uşak, Aegean Region). Coordinates of the central terrasse of the settlement: UTM 35 S 0714926/4253954 (WGS-84), 38,408˚ N, 29,4615˚ E.

From the middle of the 2nd century CE to the middle of the 6th century, Pepuza was the headquarters of the ancient Christian church of Montanism, which spread all over the Roman Empire. The Montanist patriarch resided at Pepouza, and the Montanists expected the heavenly Jerusalem to descend to earth at Pepouza and the nearbyby town of Tymion. In late antiquity, both places attracted crowds of pilgrims from all over the Roman Empire. Women played an emancipated role in Montanism. They could become priests and also bishops. In the 6th century, this church became extinct.

Since 2001, Peter Lampe of the University of Heidelberg has directed annual archaeological campaigns in Phrygia, Turkey. During these interdisciplinary campaigns, together with William Tabbernee of Tulsa, numerous unknown ancient settlements were discovered and archaeologically documented. Two of them are the best candidates so far in the search for the identification of the two holy centers of ancient Montanism, Pepuza and Tymion. Scholars had searched for these lost sites since the 19th century.