Lacus Oblivionis (Latin oblëvià Ânis, "Lake of Forgetfulness") is a small lunar mare on the surface of the Moon. It is located on the far side of the Moon at 21.0ð S, 168.0ð W and is 50 km in diameter. The name was adopted by the IAU in 1976.
The crater MohoroviÃÂiÃÂ R (satellite of MohoroviÃÂiÃÂ) lies to the northeast, and the crater Sniadecki Y (satellite of Sniadecki) lies to the southwest.