Chaos derives from the Greek Χαος and may refer to:

Science

• Chaos theory, a branch of mathematics.
• In geology, a Chaos is an area of broken terrain.
• XaoS (home page), a GPL program for real-time zooming in on fractals.

Media

• , a nonfiction book by James Gleick.
• k-os, pronounced like 'chaos', a Canadian musician.
• Chaos, a character in some of Sega's Sonic the Hedgehog video games.
• Chaos , an apocalyptic rider in the Discworld bookseries by Terry Pratchett
• In Warhammer Fantasy and Warhammer 40,000, Chaos is an army representing evil.
• Chaos, a 1984 computer game for the Sinclair ZX Spectrum and Atari ST.
• Chaos the cat, a character from the Canadian children's television show Sesame Park.
• Chaos , an enemy in Final Fantasy I.
• In Castlevania: Aria of Sorrow, Chaos is the source of the confusion and evil power within Dracula's soul.
• Chaos, a video game character in the game Xenosaga and Xenosaga II .

Myth and religion

• Chaos (also 'Khaos'), the primordial substance from which the universe sprang in Greek mythology.
• Chaos, a Chinese god.

Others

• Chaos magic, a branch of Occultism.