Bayannur or Bayannao'er is a prefecture-level city in western Inner Mongolia, People's Republic of China. Until 1 December 2003, the area was called Bayannur League.

Alxa League or Alashan League is one of 12 prefecture level divisions and 3 extant leagues of Inner Mongolia. The league borders Mongolia to the north, Bayan Nur to the northeast, Wuhai and Ordos to the east, Ningxia to the southeast, and Gansu to the south and west. The capital is Bayanhot Town, formerly known as Dingyuanying (定远营镇) or Wang Ye Fu, in the aimag's Left Banner. The Mongolian variety spoken in this area is the Alasha dialect.