A minor-planet moon is an astronomical body that orbits a minor planet as its natural satellite.

A widely accepted theory is that minor-planet moons are formed from debris knocked off of the primary by an impact.

The origin of minor-planet moons is not currently known with certainty, and a variety of theories exist.

Discoveries of minor-planet moons (and binary objects, in general) are important because the determination of their orbits provides estimates on the mass and density of the primary, allowing insights of their physical properties that is generally not otherwise possible.