Vendelinus is an ancient lunar impact crater located on the eastern edge of Mare Fecunditatis. To the north of Vendelinus is the prominent Langrenus crater, while to the southeast is Petavius crater; forming a chain of prominent craters near the eastern rim. Due to its location, the crater appears oblong due to foreshortening.

The crater is heavily worn and overlapped by multiple craters, making this feature more difficult to identify except at low sun angles. The irregular rim is broken in several locations by overlapping craters. The most prominent of these is the break in the northeast wall from the overlapping Lamé crater. The smaller Lohse crater overlaps the rim to the northwest, and at the south end the crater wall is joined to the Holden crater.

The floor of Vendelinus is flat and covered by a dark lava flow. It lacks a central peak, but includes multiple impact craters of various dimensions. Some of these are secondary craters from Langrenus, and display an oblong shape. The outer ramparts of Lamé crater forms a rise on the northeastern floor.

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 Vendelinus crater.