The Kharchin (Mongolian: ᠬᠠᠷᠠᠴᠢᠨ, Харчин, qaračin; Chinese: 喀喇沁部), or Kharachin, is a subgroup of the Mongols residing mainly (and originally) in North-western Liaoning and Chifeng, Inner Mongolia. There are Khalkha-Kharchin Mongols in Dorno-Gobi Province (Kharchin Örtöö was part of the province during Qing rule) and in Ulaanbaatar, Mongolia.

They are descended directly from the Kharchin tümen of the Northern Yuan dynasty. The Kharchin tümen consisted of:

The eastern Tümed (Chaoyang county, Liaoning) and Mongoljin (Fuxin county, Liaoning) trıbes were also categorized as Kharchin traditionally.

Exact population data of the Kharchins in China is difficult to obtain because there was a great immigration of the Kharchins for Jindandao ethnic conflict during the late Qing dynasty, and that the former Josotu league was divided after the Qing dynasty and now belongs to the present three different provinces: Inner Mongolia, Liaoning and Heibei. However, there are Liaoning's ethnic Mongols with over 600,000 population and Heibei's ethnic Mongols with over 100,000 population, both of whom are mainly originated from the Kharchins except the smaller Mongol groups with Chahar, Barga, Oirad or other ethnic origins.

The term Kharchin first appeared in the history of the Yuan dynasty. In the early 13th century, the Kipchaks and the Qanqlis surrendered to the Mongol Empire. Because they were famous for distilling khara-airag (black kumis), they were called Kharachin by the Mongols. Those Turkic peoples formed the kheshig in the Yuan dynasty after 1270. Because they formed a minority of the Mongol Yuan dynasty, they quickly assimilated with the Mongols and other groups.

By 15th century the Kharchins had formed part of Yungshiyebu tümen, inhabiting Chahar territory. In 1389 the Ming dynasty established the Doyin Uriankhain Guard in modern-day Inner Mongolia. After 1448 they resettled much closer to the Ming border. Around 1600 Kharchins moving east merged with the Doyin Uriankhai Mongols. They submitted to the Qing dynasty in 1626, and was organized into three Kharchin banners in Josogtu league, each ruled by a ruler of the Uriankhai lineage.

In the early 20th century, Prince Gungsangnorbu of the right Kharchin expanded modern education among the Mongols. The Kharchins dominated Republic of China's Mongol bureaucracy at the time. After 1945 the People's Republic of China set up new Kharchin banners outside Inner Mongolia. In 1955 the Right Kharachin (Kharchin) banner was transferred to Inner Mongolia as Kharchin banner while their central banner was abolished. The Kharchin left banner became an autonomous country in 1957.

According to a Kharchin folk legend, the Kharchin Mongols are originated from the three sub-groups: the Bornuud, the Sharnuud and the Harnuud. Bor means brown in Mongolian, and Borjigin is the family name of Genghis Khan, the Bornuud Kharchin should refer to the Yünshebü tümen (and Mongoljin-Tümed tümen) led by the successors of Genghis Khan. Shar means "yellow" in Mongolian and the Uriankhai were often called as the Yellow-head Uriankhai by other Mongols, the Sharnuud Kharchin should refer to the Doyan Uriankhai led by the famous Uriankhai general Zelme and his successors. Khar means "black" in Mongolian, and the Khitans were often named as Khara Khitans by themselves and others, the Kharnuud Kharchin should refer to the descendants of the Khitan Liao dynasty, consisted of the aboriginal Khitans and a few absorbed ethnic groups such as Jurchen and Han Chinese.