Demonstration may refer to:
- Demonstration (people), a political rally or protest
- Demonstration (proof), conclusive mathematical proof
- Scientific demonstration, a scientific experiment carried out for the purposes of illustrating principles, rather than for hypothesis testing or knowledge gathering
- Demonstration (teaching), a method of teaching by example rather than simple explanation
- A sales or marketing presentation
- Technology demo, a prototype version of a technology product, to showcase its forthcoming ideas, performance, method or features; more commonly called a demo
- Software prototyping in particular; release of a prototype version of in-progress software
- Demoware, software that users can test in a limited fashion before buying
- Game demo, more narrowly; a freely-distributed "try-out" version of a video game, usually fully playable but incomplete
- An alternate term for an exhibition game in sports
- Performance of a demonstration sport
- Demonstration of force, the show of armed forces and their capabilities