Zinc oxide is a chemical compound with the formula ZnO. It is nearly insoluble in water but soluble in acids and bases. It occurs as white hexagonal, wurtzite type crystals having 6mm of symmetry or a white powder commonly known as zinc white. Zinc oxide occurs in nature as the mineral zincite. Crystalline zinc oxide exhibits the piezoelectric effect and is thermochromic, changing from white to yellow when heated.

Zinc white is used as a pigment in paints and is more opaque than lithopone, but less opaque than titanium dioxide. It is also used in coatings for paper. Chinese white is a special grade of zinc white used in artists' pigments. Because it absorbs both UVA and UVB rays of ultraviolet light, zinc oxide can be used in ointments, creams, and lotions to protect against sunburn and other damage to the skin caused by ultraviolet light (see sunscreen). It is the broadest spectrum UVA and UVB absorber that is approved for use as a sunscreen by the FDA, and is completely photostable. It is also a main ingredient of mineral makeup.