Nuruosmaniye Mosque, located in the Çemberlitaş neighborhood of the Fatih district of Istanbul, is the first Baroque-style mosque built in Istanbul.
Built between 1748 and 1755 by Mustafa Ağa and his assistant Simeon Kalfa, the mosque is considered a turning point in Ottoman architecture. Completed during the reign of III. Osman under the name Nur-u Osmani (Light of the Ottomans), the mosque is said to be named after Sultan III. Osman and the light inside the mosque.