Ejin (Mongolian: ᠡᠵᠡᠨ᠎ᠡ ᠬᠣᠰᠢᠭᠤ; Chinese: 额济纳旗) is a banner in the far west of Inner Mongolia, China.

The ruins of the ancient city of Khara-Khoto, founded by the Western Xia, are located in Ejin.

It is located in the Gobi Desert and borders Mongolia in the north, Gansu Province in the southwest, and Alxa Right Banner in the southeast.

Ejin Banner is geographically vast—approximately the size of South Korea, it covers an area larger than each of the provinces of Jiangsu and Zhejiang.

[6] There is also a railway south to both sites (northern and southern) of Jiuquan Satellite Launch Center, which are also located within Ejin Banner.