Mongolia (Mongolian: Монгол Улс; Mongol Uls); officially the Mongolian People's Republic (Mongolian: Бүгд Найрамдах Монгол Ард Улс (БНМАУ), Bügd Nairamdakh Mongol Ard Uls (BNMAU)) is the period of Mongolian history which existed between 1924 and 1992 as a landlocked unitary sovereign socialist state in Central Asia. It was ruled by the Mongolian People's Revolutionary Party and maintained close links with the Soviet Union throughout its history.

Geographically, it bordered China to the south and the Soviet Union (Russian SFSR) to the north, and was separated from Kazakhstan by only 36.76 kilometres (22.84 mi) since the two states did not share a border.

From 1691 to 1911, Outer Mongolia was ruled by the Manchu Qing dynasty. In the first decade of the 20th century, the Qing government began implementing the so-called New Policies, aimed at a further integration of Outer Mongolia. Upset by the prospect of the colonization akin to the developments in Inner Mongolia during the 19th century, the Mongolian aristocracy turned to the Russian Empire for support. In August 1911, a Mongol delegation went to Saint Petersburg and obtained a pledge of limited support. When they returned, the Xinhai Revolution that eventually led to the collapse of the Qing dynasty had begun. In December 1911 the Mongols deposed the Qing amban in Ikh Khuree and declared their independence under the leadership of the 8th Jebtsundamba Khutuktu, who was appointed Bogd Khan of Mongolia, breaking away from the Qing dynasty. Attempts to include Inner Mongolia into the new state failed for various reasons, including the military weakness of the Inner Mongols to achieve their independence, the lack of Russian assistance to them (Russia was bound in Inner Mongolian affairs by secret treaties with Japan), and the lack of support from Inner Mongolian aristocrats and the higher clergy. In the Khiagt agreement of 1915, China, Russia and Mongolia agreed on Mongolia's status as autonomy under Chinese suzerainty.

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