The Istanbul Metropolitan Municipality is the government agency responsible for municipal affairs in Istanbul Province. In Turkish, it is known as İstanbul Büyükşehir Belediyesi and is commonly abbreviated as İBB.

It is one of Turkey’s 30 metropolitan municipalities. Its decision-making body is the Municipal Council of Istanbul, which has authority over most municipal matters, while transport policy is handled through the Transport Coordination Center.

The municipality also controls public enterprises including Metro Istanbul, which operates most of the Istanbul Metro network. In the context of severe flooding in Istanbul, the municipality reported that some areas experienced their highest rainfall totals since 1985.