Nan Geng (: 南庚, born Zi Geng , was a Shang Dynasty King of China.
In the ''Records of the Grand Historian'' he was listed by Sima Qian as the seventeenth Shang king, succeeding his cousin Zu Ding . He was enthroned in the year of Bingchen with Bi as his capital. In the third year of his reign he moved his captical to Yan . He ruled for about 29 years before his death. He was given the posthumous name Nan Geng and was succeeded by his cousin's son Yang Jia .
Oracle script inscriptions on unearthed at Yinxu alternatively record that he was the sixthteenth Shang king.