Karsiyaka, city in western Turkey, a suburb of Izmir, in Izmir province. Situated north of the Gulf of Izmir, an inlet of the Aegean Sea, Karsiyaka borders an industrial zone and a shipping yard to the east and a large forested area to the north. The city is an important business and commercial center. It is connected to downtown Izmir by rail, highway, and commuter ferry, and to Çanakkale in northwestern Turkey by highway. Originally a remote suburb of Izmir, Karsiyaka became larger and more important in the 1960s when its waterfront was developed as a prosperous residential neighborhood. Population (1990) 424,357.