The Khalkha, or Halh are a subgroup of the Mongols.

The Khalkha Mongols, together with Chahar; Ordos Mongols; and Tumed, were directly ruled by the Chingisid Khans until the 20th century; unlike the Oirats who were ruled by the Dzungar nobles or the Khorchins who were ruled by Khasar's descendants.

There were originally two major Khalkha groups, of which each ruled by the direct male line descendants of Dayan Khan.

The Baarin, Qongirat, Jaa'rut, Baigut, and the O'zeed became Dayan Khan's fifth son Achibolod's subjects, thus formed the Southern Five Khalkhas.

The Kerait, Jalair, Olkhunut, Khatagin, Besut, Iljigin, Gorlos, Uriankhai, Sartuul, Tanghut, Khotogoid, Khuree, and Tsookhor became Dayan Khan's youngest (could be third) son Geresenje's (Mongolian: Гэрсэнз Жалайр Хан) subjects, thus formed the "Аглагийн арван гурван хүрээ Халх" or The Thirteen Khalkhas of the Far North.

There were also numerous direct descendants of Genghis Khan who had formed the ruling class of the Khalkha Mongols prior to the 20th century, but they were and still also regarded as Khalkha Mongols rather than belonging to a special unit.

The Thirteen Khalkhas of the Far North are the major subethnic group of the independent State of Mongolia, or Outer Mongols.

They number 1,610,400, or 78.8 percent, of Mongolia’s population (1989 figures).

Khalkha dialect is the standard language of Mongolia.