De Roy is a lunar

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 impact crater

Impact crater

In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...

 that is located on the far side of the Moon

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

, just behind the southwestern limb. This portion of the lunar surface is brought into view during favorable libration

Libration

In astronomy, libration is an oscillating motion of orbiting bodies relative to each other, notably including the motion of the Moon relative to Earth, or of Trojan asteroids relative to planets.-Lunar libration:...

s, allowing observation of this formation. However the crater is viewed from the side when watched from the Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

, and little detail can be seen. De Roy lies to the west of the crater Arrhenius

Arrhenius (lunar crater)

Arrhenius is a lunar impact crater that is located just on the far side of the Moon, near the southwest limb. In this location the vicinity of the crater can be viewed during favorable librations, although it is viewed from on edge...

, and east of the larger Boltzmann

Boltzmann (crater)

Boltzmann is an old lunar crater that is located along the southern limb of the Moon, in the vicinity of the south pole. At this location the crater is viewed from the side from Earth, and so not much detail can be seen...

.

This crater has a worn and rounded outer rim, forming a slightly irregular circle. A pair of tiny craterlets lie along the southeast rim, and there is a narrow cleft in the northern wall. The interior floor is level and nearly featureless, with only a few tiny crater pits to mark the surface.

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 De Roy.

De Roy	Latitude	Longitude	Diameter
N	59.7° S	103.1° W	26 km
P	58.4° S	102.4° W	35 km
Q	58.1° S	103.6° W	22 km

The following craters have been renamed by the IAU

International Astronomical Union

The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...

.

• De Roy X — See Chadwick
  Chadwick (crater)
  Chadwick is a lunar crater that lies on the far side of the Moon's surface, just beyond the southwestern limb. It is located to the northwest of the crater De Roy, and was previously designated De Roy X before being given its current name by the IAU...
  
  .