Bayer is a lunar impact crater located in the southwest section of the moon, to the east of the crater Schiller. The rim of Bayer is slightly worn by erosion, but remains well-defined. There is an inner , but the outer wall is intruded upon by nearby impacts. The most significant of these is Schiller H, which forms a ridge attached to the northwest rim of Bayer. The floor of Bayer is relatively flat and lacks a central peak. There is a small, but notable crater on the floor near the western wall. This crater has a breach in its northern rim.
By convention these features are identified on Lunar maps by placing the letter on the side of the crater midpoint that is closest to Bayer.