Altai Nature Reserve (Russian: Алтайский заповедник, also called Altayskiy Zapovednik) is a Russian zapovednik ('sanctuary, strict nature reserve') in the Altai Mountains of south Siberia, Russia.

It is part of the UNESCO World Heritage Site "Golden Mountains of Altai", recognized as an area of high biodiversity and isolation from human intrusion.

[1][2] The reserve has an elongated shape running from the northeast to southwest along the Teletskoye basin and into the high interior.

The Altai reserve has been for the most part undisturbed by human activity, and is one of the few remaining pristine areas of this ecoregion.

On the slopes near Lake Teletskoye there are some secondary forests of birch and alder, but most of the reserve to the south is untouched — cedars on the site have been measured up to 1.8 metres (5 ft 11 in) in diameter and 400–450 years in age.

There are six "ecotourist" routes in the reserve, however, that are open to the public, but require permits to be obtained in advance.