De Roy is a lunar impact crater that is located on the far side of the Moon, just behind the southwestern limb.

This portion of the lunar surface is brought into view during favorable librations, allowing observation of this formation.

De Roy lies to the west of the crater Arrhenius, and east of the larger Boltzmann.

A pair of tiny craterlets lie along the southeast rim, and there is a narrow cleft in the northern wall.

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