Maslak is a neighbourhood in Sarıyer, Istanbul Province, in Turkey. Its population is 12,260 (2022). It is one of the main business districts of Istanbul, located on the European side of the city. It was formerly an exclave of the municipality of Şişli, though being far north and actually closer to the municipalities of Sarıyer and Beşiktaş. In 2012, the jurisdiction of the Maslak district was shifted from Şişli to Sarıyer.