Bandırma Gulf is a gulf on the Anatolian side of Marmara Sea in Turkey. It is administrativly a part of Bandırma ilçe (district) of Balıkesir Province.
The mid point of the gulf is at about 40°23′N 27°59′E / 40.383°N 27.983°E. Belkıs Tombolo (connecting Kapıdağ Peninsula to Anatolia mainland) is to the west, Kapıdağ Peninsula is to the north and the Marmara coast of Anatolia is to the south. Mola group of islands are to the north west of the gulf. The main settlement of the bay is Bandırma, an industrial city and a port .
The two main ferry services in the gulf are from Bandırma to Tekirdağ in the Thracean (European) part of Turkey and to Bostancı (Yenikapı) in the Anatolian part of İstanbul.