Curiosity is any natural inquisitive behaviour, evident by observation in many animal species, and is the emotional aspect of living beings that engenders exploration, investigation and learning.

In essence, "curiosity" is a term that describes an unknown number of behavioural and psychological mechanisms, which have the effect of impelling beings to seek information and interaction with their environment and with other beings in their vicinity.

Curiosity is common to human beings at all ages; from infancy to old age, and is easy to observe in many other animal species. From apes and cats to fish and reptiles and insects; many aspects of exploration are shared among all beings, as all known terrestrial beings share similar aspects; limited size, and a need to seek out food sources.

Curiosity may also refer to a novel item or phenomenon kept as an attraction to the interest of the public; it is so named because it is intended to engender curiosity in its viewers.

A morbid curiosity is a compulsion, fixed with excitement and fear, to know about macabre topics, such as death and horrible violence (snuff film).