Öndörkhaan (Mongolian: Өндөрхаан; ᠥᠨᠳᠦᠷᠬᠠᠨ; sometimes Undurkhaan), is a town in Mongolia located 290 km east of Ulaanbaatar.

Öndörkhaan experiences a semi-arid climate (Köppen BSk) with long, dry, frigid winters and short, very warm summers.

The district is divided into eight bags, which are:[5] 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 Ulaanbaatar, before the paved highway was completed.