Crown Prince Mohammed bin Salman says the 26,500 sq km (10,232 sq mile) NEOM zone will be developed in the north-west, extending to Egypt and Jordan.
It will focus on nine sectors including food technology and, energy and water.
The crown prince has been leading a drive to move Saudi Arabia away from its dependence on oil
In August, the Gulf kingdom launched a massive tourism development project to turn 50 islands and other sites on the Red Sea into luxury resorts.