Colonisation is the act where life forms move into a distant area where their kind is sparse or not yet existing at all and set up new settlements in the area. Colonisation applies to all life forms in a sense though it is most often used in reference to insects and humans. Insect colonisation varies from species to species though it most often involves a queen setting out from its parent colony and establishing a colony of her own at a suitable location.

Human colonisation is not to be confused with colonialism or imperialism, as colonisation is a broader category, encompassing all large-scale immigrations of an established population to a 'new' location, and expansion of their civilisation into this area. This process may or may not victimise an indigenous population (depending first on whether there is any indigenous population to victimise).