Helmert is a lunar impact crater at the southern edge of the Mare Smythii.

It lies near the eastern limb of the Moon, and from the Earth it is seen nearly from the side.

The visibility of this feature can be strongly affected by libration of the Moon in its orbit.

There is a gap in the rims where these two craters are joined, and the interior floors have been resurfaced by lava, leaving a level surface across the bottom of both craters.

This floor is nearly featureless, and has the same low albedo as the dark lunar mare to the north.