A moonlet, minor moon, minor natural satellite, or minor satellite is a particularly small natural satellite orbiting a planet, dwarf planet, or other minor planet.

Up until 1995, moonlets were only hypothetical components of Saturn's F-ring structure, but in that year, the Earth passed through Saturn's ring plane. The Hubble Space Telescope and the European Southern Observatory both captured objects orbiting close or near the F-ring. In 2004, Cassini caught an object 4–5 kilometers in diameter on the outer ring of the F-ring and then 5 hours later on the inner F-ring, showing that the object had orbited.

Several different types of small moons have been called moonlets:

List of moonlets