Hirami Ahmet Pasha Mosque (Turkish: Hırami Ahmet Paşa Mescidi) is a former Eastern Orthodox church converted into a mosque by the Ottomans. The small church, one among the 36 dedicated to Saint John the Baptist in Constantinople, was part of a monastery bearing the same name.[1] Its full name was Saint John the Forerunner by-the-Dome (Greek: Άγιος Ίωάννης ο Πρόδρομος έν τώ Τρούλλω, Hagios Ioannis ho Prodromos en tō Trullō). It is the smallest Byzantine church of Constantinople still extant and has never been studied.

Location
The building lies in Istanbul, in the district of Fatih, in the neighborhood of Çarşamba, one of the most (Islamic) conservative areas of the walled city. It is located in Koltutçu Sokak, along a small square, surrounded by new buildings, less than 400 m to the south of the complex of the Pammakaristos.