Corn can be fractioned to produce starch, fiber, oil, and protein in relatively pure forms. The corn kernel contains 9–12% protein, but half of this is an industrially useful protein called zein. Dry milled corn (DMC), corn gluten meal (CGM), and distiller's dried grains with solubles (DDGS) are all coproducts from corn that contain zein and are used for zein extraction. Because it is insoluble in water, zein has found uses in many products such as coatings, plastics, textiles, and adhesives. Newer applications are taking advantage of zein's biological properties for supporting growing cells, delivering drugs, producing degradable sutures, and producing biodegradable plastics. This review covers zein characteristics and nomenclature, past and current practices in processing and extraction of zein from corn products and coproducts, and the modifications of zein for various applications.