The International Court of Justice Advisory Opinion on Western Sahara was a 1975 advisory, non-binding opinion by the International Court of Justice (ICJ) of two questions presented to it by the UN General Assembly under Resolution 3292 regarding the disputed territory of Western Sahara (then Spanish Sahara). Morocco had approached the UN to adjudicate its and Mauritania's claims over the territory.

The ICJ deliberated between 13 December 1974 and 16 October 1975. The final ruling by the Court stated that:

The materials and information presented to it [the ICJ] do not establish any tie of territorial sovereignty between the territory of Western Sahara and the Kingdom of Morocco or the Mauritanian entity. Thus the Court has not found legal ties of such a nature as might affect the application of resolution 1514 (XV) in the decolonization of Western Sahara and, in particular, of the principle of self-determination through the free and genuine expression of the will of the peoples of the Territory (ICJ Reports 16 October 1975, 162).