Kapetyn is a lunar impact crater that is near the eastern limb of the Moon, to the west of the crater La Pérouse. West of Kapetyn is the slightly smaller Barkla, and farther to the west-northwest is the prominent Langrenus. This crater is circular in shape, although it appears oval when viewed from the Earth due to foreshortening. The rim is only slightly worn, with no craters of note along the edge or the inner walls. There is a shelf along the eastern inner wall. At the midpoint of the interior floor is a central peak.