Sultanbeyli is a municipality and district of Istanbul Province, Turkey. Its area is 29 km2, and its population is 358,201 (2022). It is located inland on the Asian side of the city. The mayor is Ali Tombaş of the Justice and Development Party. Sultanbeyli is a landlocked district, bordered by Sancaktepe to the west, Pendik to the east and Kartal to the south-west.

Pendik is a municipality and district of Istanbul Province, Turkey. Its area is 190 km2, and its population is 750,435 (2022). It is on the Asian side between Kartal and Tuzla, on the Marmara Sea. It also neighbours Sultanbeyli, Sancaktepe and Çekmeköy from northwest, Şile from north and Gebze from northeast. The district is home to the Sabiha Gökçen International Airport.