Otgontenger (/ˌɒtɡɒnˈtɛŋɡər/; Mongolian: Отгонтэнгэр [ˈɔʰtχɞɴtʰɪŋɡɪ̆r]; lit. 'The Youngest Sky') is the highest peak in the Khangai Mountains in Mongolia. Its summit is currently calculated to reach an elevation of 4,008 meters above mean sea level (some earlier topographic maps record a maximum elevation of 4,021 m). The mountain is located in Zavkhan Province and is the only peak in the Khangai range that is capped with a permanent glacier. The south face of Mount Otgontenger is the most extensive granite wall in Mongolia. The Ötüken Mountain is considered sacred by ancient Turks.

Since the introduction of Buddhism, traditional Mongolian beliefs have held that wrathful deities inhabit many of Mongolia's sacred mountains. Ochirvaani is particularly associated with Otgontenger.

On 4 August 1963, MIAT Mongolian Airlines Avia 14 Super MONGOL-105 struck the side of the mountain while on route, killing all on board.

In October 2017, 27 hikers climbed the mountain and only 10 of them came back. They requested the rescue team a day after the other 17 went missing. The rescue operation took about 4 days with helicopters and 250 men. Rescuers found all 17 of them dead, having received injuries from both fall damage and from frostbite. However, it was still argued that some of the victims survived the fall and tried to send distress signals by using flashlights.

• Otuken
• List of mountains in Mongolia
• List of Ultras of Central Asia

• "Otgon Tenger Uul, Mongolia" on Peakbagger
• www.summitpost.org/otgon-tenger-uul summitpost/otgon tenger