Orog Lake, or Orog Nuur (Mongolian: Орог нуур) is a lake located in the district of Bogd, in Bayankhongor Province, Mongolia.

The shores are low and sandy, with salt marshes in some places.

Fresh or salt water predominates depending on the amount of rainfall.

[1] Uranium and arsenic accumulate in this lake during evaporation, although, under very dry conditions, some As(V) reacts with ferrihydrite and is removed.

This article related to a lake in Mongolia is a stub.