Ring 0 or zero ring or variation, may refer to:
Arts and entertainment
- Ring 0: Birthday, a Japanese horror prequel film
- The Ring Volume 0: Birthday, a subsequent manga
Technology
- Ring 0 (computer security), the highest privilege level
- Telephone dialling instructions to access a switchboard operator
Other uses
- Zero ring, the trivial ring in mathematics ring theory
- O̊, the letter "O" with a ring diacritical mark
See also
- Birthday (short story collection), a Japanese anthology containing prequels and sequels to Ring
- Ring road (disambiguation)
- Ring (disambiguation)