Ayvansaray is a neighborhood in Istanbul, Turkey. It is part of the district of Fatih and part of the walled city. It lies between the southern shore of the Golden Horn, the Blachernae section of the Walls, and the neighborhoods of Balat and Edirnekapı. It corresponds to the old quarter of Blachernae (Vlachèrnae in Greek). The name Ayvansaray ("High Palace") hearkens back to the Palace of Alexios I Komnenos (now disappeared), which was part of the complex of Blachernae.
Ayvansaray has some monuments, like the mosque of Atik Mustafa Pasha (an ancient Byzantine church), and the Ayazma ("holy spring") enclosed in the small church of St. Mary of Blachernae. It is a picturesque quarter.