Boethius is a small lunar impact crater located on the east edge of Mare Undarum near the eastern lunar limb. To the southwest is the dark, lava-flooded crater Dubyago.
Boethius is circular and cup-shaped, with inner walls sloping down to the tiny central floor. It has a higher albedo than the surrounding terrain, and is not overlain by other impact craters of note. Boethius was identified as Dubyago U before being named by the IAU.