Körfez is a town and district of the Kocaeli Province in the Marmara region of Turkey. The mayor is Yunus Pehlivan (AKP). It was created from eastern part of Gebze and western part of İzmit (Then called Center) districts in 1987. It has borders with Şile to north, Derince from east, Dilovası from southwest and Gebze from west. Its center was called Yarımca before a district center.