Possibility is the quality of being possible and may refer to:
- Probability, the measure of the likelihood that an event will occur
- Epistemic possibility, a topic in philosophy and modal logic
- Possibility theory, a mathematical theory for dealing with certain types of uncertainty and is an alternative to probability theory
- Subjunctive possibility, (also called alethic possibility) is a form of modality studied in modal logic.
- Logical possibility, a proposition that will depend on the system of logic being considered, rather than on the violation of any single rule
- Possible world, a complete and consistent way the world is or could have been
