Luther is a small lunar impact crater on the northwest part of Mare Serenitatis, at the inlet to Lacus Somniorum.

Luther has a circular rim and is cup-shaped, with no appreciable wear from impact erosion.

It lies across a wrinkle ridge on the lunar mare.

The crater is named after German astronomer Robert Luther.

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