Krypton is a fictional planet in the DC Comics universe, and the native world of the super-heroes Superman and, in some tellings, Supergirl and Krypto the Superdog. Krypton has been portrayed consistently as having been destroyed just after Superman's flight from the planet, with exact details of its destruction varying by time period, writers and franchise. Kryptonians were the dominant people of Krypton.

The planet was created by Jerry Siegel and Joe Shuster, and was first referred to in Action Comics #1 (June 1938); the planet was given its first full-fledged appearance in Superman #1 (Summer 1939).

Krypton is usually portrayed in comics as having exploded as a result of a nuclear chain reaction caused by the planet's unstable radioactive core (which created the Superman-deadly Kryptonite). As originally depicted, all the civilizations and races of Krypton perished in the explosion, except for one survivor: the baby Kal-El who was placed in an escape rocket by his father, Jor-El, and sent to the planet Earth, where he grew up to become Superman.

Krypton ( /ˈkrɪptɒn/ KRIP-ton; from Greek: κρυπτός kryptos "the hidden one") is a chemical element with the symbol Kr and atomic number 36. It is a member of Group 18 and Period 4 elements. A colorless, odorless, tasteless noble gas, krypton occurs in trace amounts in the atmosphere, is isolated by fractionally distilling liquified air, and is often used with other rare gases in fluorescent lamps. Krypton is inert for most practical purposes.

Krypton, like the other noble gases, can be used in lighting and photography. Krypton light has a large number of spectral lines, and krypton's high light output in plasmas allows it to play an important role in many high-powered gas lasers (krypton ion and excimer lasers), which pick out one of the many spectral lines to amplify. There is also a specific krypton fluoride laser. The high power and relative ease of operation of krypton discharge tubes caused (from 1960 to 1983) the official length of a meter to be defined in terms of the 605 nm (red-orange) spectral line of krypton-86.