Lyman is a lunar impact crater that lies in the southern hemisphere on the far side of the Moon.

The rim of Lyman has not been significantly worn and has a well-defined edge and interior features that have not been eroded through impacts.

The perimeter is roughly circular with outward bulges along the southern and eastern edges where slumping has occurred.

The interior floor of Lyman is relatively level with a few minor ridges and a small number of tiny craterlets.

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