East of the Hijaz and Asir lies the great plateau area of Najd. This region is mainly rocky plateau interspersed by small, sandy deserts and isolated mountain clumps. The best known of the mountain groups is the Jabal Shammar, northwest of Riyadh and just south of the An Nafud. This area is the home of the pastoral Shammar tribes, which under the leadership of the Al Rashid were the most implacable foes of the Al Saud in the late nineteenth and early twentieth centuries. Their capital was the large oasis of Hail, now a flourishing urban center.

Across the peninsula as a whole, the plateau slopes toward the east from an elevation of 1,360 meters in the west to 750 meters at its easternmost limit. A number of wadis cross the region in an eastward direction from the Red Sea escarpment toward the Persian Gulf. There is little pattern to these remains of ancient riverbeds the most important of them are Wadi ar Rummah, Wadi as Surr, and Wadi ad Dawasir.

The heart of Najd is the area of the Jabal Tuwayq, an arc-shaped ridge with a steep west face that rises between 100 and 250 meters above the plateau. Many oases exist in this area, the most important of which are Buraydah, Unayzah, Riyadh, and Al Kharj. Outside the oasis areas, Najd is sparsely populated. Large salt marshes (sabkah) are scattered throughout the area.

Data as of December 1992