Lanthanum oxide is an inorganic compound with the chemical formula La2O3, and is a white powder. Soluble in acids, ethanol, and ammonium chloride, insoluble in water and ketones. The application of rare earth lanthanum oxide is very extensive, and it plays an important role in the fields of glass, ceramics, electronics, etc.

Mainly used for manufacturing precision optical glass and optical fibers. Also used in the electronic industry as ceramic capacitors and piezoelectric ceramic additives. It is also used as a raw material for the production of lanthanum borate and a catalyst for petroleum separation and refining.