Humour or humor is the tendency of particular cognitive experiences to provoke laughter and provide amusement. Many theories exist about what humour is and what social function it serves. People of most ages and cultures respond to humour. The majority of people are able to be amused, to laugh or smile at something funny, and thus they are considered to have a "sense of humour."

The term derives from the humoural medicine of the ancient Greeks, which stated that a mix of fluids known as humours (Greek: ?�?�?????�, chymos, literally juice or sap; metaphorically, flavour) controlled human health and emotion.