Dornod (Mongolian: Дорнод, [ˈtɔrnɞt]; lit. "East") is the easternmost of the 21 aimags (provinces) of Mongolia. Its capital is Choibalsan.

Halh are the ethnic majority of the Dornod aimag. The Buryat ethnic group makes up 22.8% of the total population (17,196 in 2000, census) concentrated in the north-eastern sums of Dashbalbar, Tsagaan-Ovoo, Bayan-Uul, Bayandun and aimag capital Choibalsan. There are several small ethnic groups: Barga (populates Gurvanzagal and Hölönbuir sums), Uzemchin (are present in Sergelen, Bayantümen, Bulgan, Chuluunhoroot sums and Choibalsan city), Hamnigan ethnic group (Bayan-Uul and Tsagaan-Ovoo sums).^[3]

The aimag was created during the administrative reorganisation of 1941 with the name of Choibalsan, after the communist leader Khorloogiin Choibalsan. The capital, which previously had been called Bayan Tümen, also received the name Choibalsan. In 1963, the aimag was given the current name Dornod.

Dornod Province is situated in the easternmost region of Mongolia and shares borders with Russia and China. It covers an area of approximately 123,597 square kilometers (47,746 square miles). The landscape of Dornod is diverse, featuring grasslands, mountains, and rivers.

The Choibalsan International Airport (COQ/ZMCD) has one paved runway, and is served by regular flights to Ulaanbaatar and Hailar, China.

^1 - Sum center is aimag capital Choibalsan (Чойбалсан)

• Chimediin Saikhanbileg, prime minister of Mongolia
• Kirishima Tetsuo, sumo wrestler at ozeki rank