Aliacensis is a lunar impact crater that is located in the rugged southern highlands of the Moon. The Werner crater is located just to the north-northwest, and a narrow, rugged valley lies between the two comparably-sized formations. To the southwest is the Walther crater, and Apianus crater is located to the northeast.

The rim of Aliacensis is generally circular, with an outward bulge on the eastern wall. The inner wall has some slight terracing particularly in the northeast. There is a small crater located across the southern rim. The interior floor is generally flat, with a low central peak slightly offset to the northwest of the mid-point.

Satellite craters

By convention these features are identified on Lunar maps by placing the letter on the side of the crater mid-point that is closest to Aliacensis crater.