Biological pest control is a rapidly expanding field of agriculture, where natural agents, primarily parasitoids and predators are used to control a pest organism that has been causing economic harm to human interests. These methods can be as alternatives or supplements to conventional pest control methods such as insecticides. Human disturbance of ecology ecological systems, particularly the development of monoculture and the movement of species tends to stimulate pest problems by reducing biodiversity which usually has natural controls that keep pest populations in line. Biological pest control does not seek to eradicate pests, but to keep them to economically minimal factors by reducing populations to acceptable levels.

Some organisms have been intesively studied and are in modern commercial use. Many other organisms have potential and are candidates for use in this field. This category includes both current and potential biologicial control agents. See subcategory - Biological pest control agent.