Monotone refers to a sound, for example speech or music, that has a single unvaried tone.
Monotone or monotonicity may also refer to:
- Monotone (software), an open source revision control system
- Monotone class theorem, in measure theory
- Monotone convergence theorem, in mathematics
- Monotone polygon, in geometry
- Monotone preferences, in consumer economics
- Monotonicity criterion, a voting system criterion
- Monotonic function, mathematical concept
- Monotonic orthography, simplified spelling of modern Greek
- Monotonicity of entailment, property of some logical systems
- The Monotones, American rock 'n' roll band (1950s)