| Öndörkhaan | |
| Native Name: | Өндөрхаан |
| Native Name Lang: | mn |
| Settlement Type: | District |
| Official Name: | Хэрлэн сум |
| Pushpin Map: | Mongolia |
| Subdivision Type: | Country |
| Subdivision Name: | Mongolia |
| Subdivision Type1: | Province |
| Subdivision Name1: | Khentii Province |
| Area Total Km2: | 3788 |
| Population As Of: | 2017 |
| Population Total: | 20935 |
| Population Density Km2: | auto |
| Timezone: | UTC + 8 |
| Utc Offset: | +8 |
| Coordinates: | 47.3167°N 149°W |
| Elevation M: | 1027 |
Öndörkhaan (Mongolian: Өндөрхаан; ; sometimes Undurkhaan), is a town in Mongolia located 290 km east of Ulaanbaatar. On November 18, 2013, the city was renamed to Chinggis City in honor of Genghis Khan, who was born and possibly buried in the same province north of the city.[1] Öndörkhaan serves as the capital of the province Khentii Aimag.
On 13 September 1971, Lin Biao died when a Hawker Siddeley Trident he was aboard crashed in Öndörkhaan.
Öndörkhaan shares its location with the Kherlen sum (municipality) and is the most populous part of the Khentii province.
Öndörkhaan experiences a semi-arid climate (Köppen BSk) with long, dry, frigid winters and short, very warm summers. It borders the Kherlen River and is located on a broad flat unprotected plain. In winter, when the river freezes over and the winds howl across the open steppe it can easily reach NaNC without the subtraction of wind chill.
Coal mining is important to the economy of the town and Chandgana Tal coalfield is located 53 km W from Öndörkhaan.
There exists a major United Nations Development Programme (UNDP) Networking and Cluster Development project stationed in Öndörkhaan specializing in the strengthen of urban, peri-urban and rural business associations and networks so as to reduce the very high unemployment rates.
The Öndörkhaan Airport (UNR/ZMUH) has one unpaved runway and was serviced by regular flights from and to Ulan Bator, before the paved highway was completed.
The town serves as a transportation hub, linking Ulaanbaatar and Choibalsan.