What is the large region of icy bodies beyond Neptune called?

The large region of icy bodies beyond Neptune is called the Kuiper belt. It is a broad, flattened disk of remnants left over from the Solar System’s formation, extending roughly from Neptune’s orbit at 30 astronomical units to about 50 astronomical units from the Sun.

Kuiper belt objects are rich in frozen materials such as water, methane, and ammonia. The region includes Pluto, Haumea, Makemake, Quaoar, and many smaller bodies. Pluto’s location in this distant population helped establish why it is classified as a dwarf planet rather than one of the eight major planets.

The Kuiper belt is often confused with the Oort cloud. The Kuiper belt is relatively close, disk-shaped, and associated with many short-period icy bodies. The hypothesized Oort cloud is vastly more distant and is expected to surround the Solar System in a roughly spherical shell.

The belt is named after astronomer Gerard Kuiper, although Kenneth Edgeworth and later Julio Fernández also made important contributions to the idea. The first confirmed Kuiper belt object discovered after Pluto was found in 1992.