Methacrylic acid (MAA) is an organic compound with the formula CH2=C(CH3)COOH. It is one of the simplest unsaturated carboxylic acids and is an important industrial chemical. MAA is a colourless liquid with a sharp, acrid odour. It is soluble in water, alcohol, and ether.

MAA is produced by the oxidation of methacrolein. It can also be produced by the hydrolysis of methyl methacrylate.

MAA is used in the production of a variety of polymers, including poly(methyl methacrylate) (PMMA), which is a clear, hard plastic. PMMA is used in a variety of applications, including windows, skylights, and dentures.

MAA is also used in the production of adhesives, coatings, and inks. It is also used as a comonomer in the production of other polymers, such as styrene-butadiene rubber.

MAA is a hazardous material and can cause skin and eye irritation. It is also flammable and can be explosive.

The global market for MAA was estimated to be worth US$3.2 billion in 2019. The market is expected to grow at a CAGR of 4.2% from 2019 to 2025.