甲基丙烯酸，结构式H₂C＝C(CH₃)COOH。

甲基丙烯酸在常温下为无色透明液体。易溶于热水、乙醇和大多数有机溶剂。易聚合。其蒸气可与空气形成爆炸性混合物。具中等毒性，对皮肤和粘膜有较强的刺激性，但未见致癌现象。

Methacrylic acid, abbreviated MAA, is an organic compound. This colorless, viscous liquid is a carboxylic acid with an acrid unpleasant odor. It is soluble in warm water and miscible with most organic solvents. Methacrylic acid is produced industrially on a large scale as a precursor to its esters, especially methyl methacrylate (MMA) and poly(methyl methacrylate) (PMMA). The methacrylates have numerous uses, most notably in the manufacture of polymers with trade names such as Lucite and *********. MAA occurs naturally in small amounts in the oil of Roman chamomile.