| Choir | |
| Native Name: | Чойр |
| Native Name Lang: | mn |
| Settlement Type: | District |
| Official Name: | Сүмбэр сум |
| Pushpin Map: | Mongolia |
| Pushpin Label Position: | right |
| Pushpin Map Caption: | Location in Mongolia |
| Subdivision Type: | Country |
| Subdivision Name: |  Mongolia |
| Subdivision Type1: | Province |
| Subdivision Name1: | Govisümber |
| Subdivision Type2: | Sum |
| Subdivision Name2: | Sümber |
| Area Total Km2: | 916 |
| Population As Of: | 2017 |
| Population Total: | 10434 |
| Population Density Km2: | auto |
| Timezone: | UTC+8 |
| Coordinates: | 46.3606°N 108.365°W |
| Elevation M: | 1279 |
| Area Code: | (+976) 154 |
| Blank Name: | Climate |
| Blank Info: | BSk |
Choir (; Mongolian: Чойр, in Mongolian pronounced as /ˈt͡ɕœe̯r/) is a city in east-central Mongolia. It is the capital of Govisümber Province. Choir is officially known as Sümber sum.
Choir was a military base during the Soviet period. In 1989, the Soviet anti-aircraft missile units left Choir.[1] The longest runway in Mongolia, now abandoned, is located 25 km N from Choir, a relic of that period.[2] In 1992, the military cantonment passed into the jurisdiction of Govisümber Province, according to the 1992 constitution.[3] Near the railway station is a statue commemorating Mongolia's first cosmonaut, Jügderdemidiin Gürragchaa.
Choir lies in the Choir Depression, a lowland strip about 150 km long and 10 to 20 km wide, about 500 m lower than the surrounding upland.[4] It lies at an altitude of 1269 m.
Choir has a semi-arid climate (Köppen climate classification BSk) with warm summers and severely cold winters. Most precipitation falls in the summer as rain, with some snow in the adjacent months of May and September. Winters are very dry.
In 2002, a population of Choir city was 7,588 (and 9,207 with rural parts of Sümber sum),[5] up from a population of 4,500 in 1979.[6] For the end of 2006 estimations population was 7,998.[7]
Choir has been declared a free enterprise zone.[2] Along with Darkhan and Erdenet, it is one of three autonomous cities in Mongolia.[8] Choir has a medium-security prison which can house 460 prisoners.[9]
It lies along the Trans-Mongolian Railway, 250 km to the southeast of Ulan Bator. The Asian Development Bank is considering a 430-km paved road from Choir to the Chinese border, the final stage of a north-south route through the country.[10]