SS Peter and Paul is a Catholic church in Istanbul, important for historical reasons. The church owns an icon of the Virgin of the Hodegetria type, which originally lay in a Dominican church in Caffa, Crimea. The current building is a nineteenth-century reconstruction of the Fossati brothers. An adjacent former commercial facility, Saint Pierre Han, is set to be renovated into a cultural center.

The Fossati brothers, Gaspare and Giuseppe (1822–1891), were Swiss architects. They completed more than 50 projects in Turkey during the Tanzimat era. They belonged to the Morcote branch of the Fossati, a prominent Ticinese family with mentions in the historical record going back to the 14th century. Gaspare is most noted for his renovation of the Hagia Sophia in Constantinople, which virtually saved it from destruction.