Acetone is a colorless, flammable, and volatile liquid with a characteristic odor that can be detected at very low concentrations. It is used in consumer goods such as nail polish remover, model airplane glue, lacquers, and paints. Industrially, it is used mainly as a solvent and an ingredient to make other chemicals.

Acetone is the common name for the simplest of the ketones. The formula of acetone is CH₃ CO CH₃.

The International Union of Pure and Applied Chemistry's (IUPAC) systematic name for acetone is 2-propanone; it is also called dimethyl ketone. The molecular weight is 58.08. Its boiling point is 133°F (56°C) and the melting point is -139.63°F (-95.4°C). The specific gravity is .7899.

Acetone is the simplest and most important of the ketones. It is a polar organic solvent and therefore dissolves a wide variety of substances. It has low chemical reactivity. These traits, and its relatively low cost, make it the solvent of choice for many processes. About 25% of the acetone produced is used directly as a solvent.

About 20% is used in the manufacture of methyl methacrylate to make plastics such as acrylic plastic, which can be used in place of glass. Another 20% is used to manufacture methyl isobutyl ketone, which serves as a solvent in surface coatings. Acetone is important in the manufacture of artificial fibers,explosives, and polycarbonate resins.

Because of its importance as a solvent and as a starting material for so many chemical processes, acetone is produced in the United States in great quantities. In 1999, the worldwide acetone market reached 9.4 billion lb (4.27 billion kg) at a steady growth rate of 2-3% per year. Acetone is prepared by several routes, from petrochemical sources. The methods of its synthesis include oxidation of 2-propanol (isopropyl alcohol), the hydration of propene, and as a co-product (with phenol) of the O₂-oxidation of cumene.

Acetone is normally present in low concentrations in human blood and urine. Diabetic patients produce it in larger amounts. Sometimes "acetone breath" is detected on the breath of diabetics by others and wrongly attributed to the drinking of liquor. If acetone is splashed in the eyes, irritation or damage to the cornea will result. Excessive breathing of fumes causes headache, weariness, and irritation of the nose and throat. Drying results from contact with the skin.