Christians in Mongolia are considered a minority group. Accounts of the exact number of Christians vary as no nationwide statistics have even been released. In 1991 there were 0 christians, any numbers since them resulting from missionary work, mainly originating in the US. As of 2005, the United States Department of State reports that approximately 24,000 Christians live in Mongolia's capital, Ulaan Baatar, which is around 3 percent of the entire registered population of the city. In reality many coverts lapse after a few years, due to the lack of a christian tradition in Mongolia and the lack of cultural awareness of many missionaries.

With the end of Mongolia's communist regime in 1990, numbers of Christian followers have started to steadily increase again. Foreign Christian missionary groups have also returned to Mongolia, including Roman Catholics, Lutherans, Presbyterians, various evangelical Protestant groups, the Church of Jesus Christ of Latter-day Saints (Mormons), Jehovah's Witnesses, and Seventh-day Adventists.

Nestorianism

Nestorianism is the one version of Christianity that can have any claim to a legitimate, if small, place in Mongolian history.

During the 7th century, as activities of the Assyrian Church of the East after the Nestorian Schism expanded eastwards, Nestorianism became the first form of Christianity to be introduced in Mongolia.  Little is known of early Nestorianism other than from hostile catholic sources. Nestorianism derived it's name from the historical figure of Nestorius, and the sect was regarded as heretical by western churches. Many Nestorians fled east due to persecution in the Byzantine empire, and their belifs spread from Syria to the Persian Empire, and then on to China during the late Tang period. The turkish and Mongol groups of the present Mongolian area saw some influence, for example amoungst the Khereyid Mongols of the central Mongolian region.

The Naimen and Khereyid tribes did undergo some Nestorian influence, yet the Mongolian Epic, The secret History of the Mongols, describes these tribes as being shamanistic. once these tribes were absorbed into the Mongolian empire, members of these tribes exerted some influence in wider Mongol society. For instance, Sorkhagtani, the wife of the fourth son of chinggis khaan and the mother of two important figures, Mongke and Khubilai, was converted to Nestorianism. In Tents and temples in Inner Mongolia, published in 1951, it is reported that small shrines to Sorkhatani could still be found in Buddhist temples in the mid 1940's !