Proclus is a young lunar impact crater located to the west of the Mare Crisium on the east shore of the Palus Somni.

Its diameter is 27 km and it was named after 5th century Greek mathematician, astronomer and philosopher Proclus.

[1] It lies to the south of the prominent, terraced crater Macrobius, and west-northwest of the lava-flooded Yerkes.

[2] A candidate landing site for the Apollo program was located about 100 km north-northeast of Proclus.

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