In politics, interventionism is a term for significant activity undertaken by a state to influence something not directly under its control. The most common applications of the term are for economic interventionism (a state's intervention in its own economy) and foreign interventionism (a state's intervention in the affairs of another nation).

Interventionism, when discussing the practice of medicine, is generally a derogatory term used by critics of a medical model in which patients are viewed as passive recipients receiving external treatments provided by the physician that have the effect of prolonging life.