0K (zero K) or 0-K may refer to:
- 0k, an abbreviation for zero killed (used by bombers during World War II)
- 0K, an abbreviation for the temperature zero Kelvin, or Absolute zero
- 0K, an abbreviation for Zero knowledge in cryptology
- 0K, an abbreviation for zero keel, a type of Suspension keel
- Zero-K, an open source real time strategy game
- Zero K, a novel by Don DeLillo
- Zero K, Music producer