MINURSO is the United Nations peacekeeping mission in Western Sahara. The name is a French acronym for "Mission des Nations Unies pour l'Organisation d'un Référendum au Sahara Occidental" — United Nations Mission for the organization of a Referendum in Western Sahara.

MINURSO was established in 1991 under Security Council Resolution 690, as part of the Settlement Plan, which had paved way for a cease-fire in the conflict between Morocco and the Polisario Front (as the Sahrawi Arab Democratic Republic), over the contested territory of Western Sahara (formerly Spanish Sahara).

MINURSO's mission was to monitor the cease-fire and to organize and conduct a referendum, in accordance with the Settlement Plan, which would enable the Sahrawis of Western Sahara to choose between integration with Morocco and independence. This was intended to constitute the Sahrawi people's exercise of self-determination, and thus complete Western Sahara's still-unfinished process of decolonization (Western Sahara is the last major territory remaining on the UN's list of non-decolonized territories.)