Piazzi Smyth is a small lunar impact crater in the eastern part of the Mare Imbrium. It was named after Scottish astronomer Charles Piazzi Smyth. This is an isolated feature located about 100 kilometers to the southwest of the Montes Alpes mountain range. To the southeast of this crater is Mons Piton, an isolated mountain that rises to a height of 2.3 km and occupies a diameter of about 25 km.