The Kılıç Ali Pasha Mosque (Turkish: Kılıç Ali Paşa Cami) is a mosque at the heart of a complex designed and built between 1580 and 1587 by Mimar Sinan, who at the time was in his 90s. The mosque itself was constructed in 1578-1580.

The complex is located in the Tophane neighbourhood of the Beyoğlu district of Istanbul, Turkey. It was built for the Kapudan-i Derya (Grand Admiral) Kılıç Ali Pasha who was told to build it beside the sea because he was an admiral. . The complex consists of a mosque, a medrese, a hamam, a türbe, and a fountain.

The Kılıç Ali Pasha Mosque originally stood right beside the Bosphorus, but since the water in front of it has since been filled in, it is now surrounded by other buildings (in particular it now faces the Galataport cruise terminal).

The central dome of the mosque is 12.70 metres (41.7 ft) in diameter, carried on pendentives on granite piers and two half-domes on the Qibla axis. Towards the entrance, on two sides, there is a two-storey gallery. The dome is placed at the center with two exedrae rather like a Byzantine basilica, thus the resemblance to Hagia Sophia.

Above the prayer hall are five small domes carried on six marble columns. The tile panels placed high up in the prayer hall are inscribed with ayats (verses) from the Quran. The mosque has only one minaret with one gallery but there are 247 windows including the twenty-four of the central dome. The mihrab is in a square projecting apse.

A 16th-century ship lamp that used to hang from the central dome was removed to the Museum of Ottoman and Turkish Naval History (now the Istanbul Naval Museum/Deniz Müzesi) in 1948.

Two chronograms in the mosque both date it to 988 in the Hijri (Islamic) calendar (1580 in the Julian calendar).

The letters in the final line - 'May this be a house of worship for people of the faith' - add up to the number 988.

The courtyard contains a marble fountain for ablutions before prayer with eight columns and a dome. The outer porch has a sloping roof supported by twelve columns on the west façade and three at each end, all with rhombus-shaped capitals. In the center a marble portal leads into the mosque.

The graveyard contains the octagonal türbe of Kılıç Ali Pasha with a dome designed by Mimar Sinan. Its wooden doors are inlaid with mother-of-pearl.