0S (zero S) or 0-S may refer to:
- 0s, the decade from January 1, 1 AD to December 31, 9 AD.
- 1st century, the century from January 1, 1 AD to December 31, 99 AD.
- 1st millennium, the millennium from January 1, 1 AD to December 31, 999 AD.
- 0S, 0°S, or zero degrees south, coordinate for the equator
- Zero S, a model of electric motorcycle
- 0 set, or zero set, a concept in mathematics
- 0 sum, or zero-sum, a theory in games and economics
- 0 sharp, also zero sharp or 0#, a concept in set theory
- 0 section, or zero section, a type of section in a Vector bundle