Brunner is a lunar impact crater that is located along the eastern limb of the Moon, to the southeast of the Mare Smythii.

At this location the crater is viewed from the edge, and so it is not possible to see much detail from the Earth.

The rim of Brunner is well-defined and nearly circular, although there is a slight outward bulge and a depressed wall along the north.

The interior of the crater is rugged and irregular, with a central ridge formation at the midpoint.

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