The Eyüp Sultan Mosque (Turkish: Eyüp Sultan Camii) is an ancient Ottoman mosque located in the Eyüp region on the European side of Istanbul, near the Golden Horn, and is located outside the walls of Constantinople. The mosque was built in 1458, five years after the conquest of Constantinople, and it is the first A mosque built by Muslims in Istanbul after the conquest of Constantinople in 1453.

The current building dates from the beginning of the 19th century. The mosque complex outside includes a separate building containing the tomb of the great companion Abi Ayyub Al-Ansari (may God be pleased with him) for those who wanted to visit him, and many other graves outside the complex.

The great companion Abu Ayyub al-Ansari was buried there when the Muslims tried to conquer Constantinople in the year 52 AH, but they did not succeed in that. Many Muslims visit his shrine out of respect for him, and some of the belongings of the Prophet Muhammad, may God bless him and grant him peace, are found in that shrine outside the mosque.

Sheikh Aq Shams al-Din discovered the lost tomb for centuries of the great companion Abu Ayyub al-Ansari (companion of the Prophet Muhammad) outside the walls of Constantinople before the siege of Constantinople.

The Turks call the great companion Abu Ayyub al-Ansari the name “Ayyub Sultan” in appreciation and love for him.