Corn oil is a vegetable oil extracted from the germ of the grains of yellow corn Zea mays L., and is a by-product of the corn flour and corn starch industry. A single corn grain contains only 4-5% oil by weight, but the germ contains 80% of this oil, so it is first separated by wet milling and then pressed to obtain the oil.

Corn cultivation has a history extending more than nine thousand years in Mexico and Central America. However, extracting oil from corn germ actually began in the United States in the late nineteenth century as the corn starch industry developed. The United States remains the largest producer in the world, followed by China, Brazil, and Turkey.

Corn oil has a composition rich in linoleic acid (50-60% omega-6), then oleic acid (25-35%), and palmitic acid (12%), with an omega-6:omega-3 ratio of 50:1. It also contains phytosterols and vitamin E in high proportions. It has a high smoke point of up to 230°C, a light golden-yellow color, and a neutral flavor.

The United States leads corn oil production globally, but the output is not included in USDA-FAS data for the main vegetable oil market because of its relatively small size. The oil is classified as a specialty oil despite its wide presence in commercial kitchens. It is governed by Codex Alimentarius standard CXS 210-1999.

Corn oil is used in commercial cooking and frying (especially potato chips and popcorn), and in the making of mayonnaise, sauces, broths, and margarine. Industrially, it goes into the making of soap and cosmetics, paints, biofuel, and as an excipient for pharmaceuticals.