Maskelyne is a solitary lunar impact crater that lies in the southeast part of the Mare Tranquillitatis.

The inner walls are terraced and there is a low central rise at the midpoint of the floor.

Tranquility Base, the landing site of the 1969 Apollo 11 expedition, is located about 250 kilometers to the west-southwest.

To the south are the lunar mountains informally known as Duke Island and Boot Hill.

By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Maskelyne.