The mission civilisatrice, a French term which translates literally into English as "civilizing mission" (Portuguese: Missão civilizadora, also French: œuvre civilisatrice), is a rationale for intervention or colonization, purporting to contribute to the spread of civilization, and used mostly in relation to the Westernization of indigenous peoples in the 19th and 20th centuries.
It was notably the underlying principle of French and Portuguese colonial rule in the late 19th and early 20th centuries. It was influential in the French colonies of Algeria, French West Africa, and Indochina, and in the Portuguese colonies of Angola, Guinea, Mozambique, and Timor. The European colonial powers felt it was their duty to bring Western civilization to what they perceived as backward peoples. Rather than merely govern colonial peoples, the Europeans would attempt to Westernize them in accordance with a colonial ideology known as "assimilation".
For example, in 1883 on the Occupation of Araucanía, Chilean president Domingo Santa María stated: "Today all Araucanía is subjugated, more than to the material forces, to the moral and civilizing force of the republic".