恶唑（Oxazole）是一大类有机杂环化合物的母体，含有一个氧杂原子和一个氮杂原子。

在生物化学中，由丝氨酸和苏氨酸非核糖体多肽环化然后氧化就可以得到恶唑。

在生物体内，恶唑并不像噻唑那样普遍，后者是恶唑的类似物，用硫原子取代恶唑中的氧原子。

Oxazole is the parent compound for a vast class of heterocyclic aromatic organic compounds. These are azoles with an oxygen and a nitrogen separated by one carbon. Oxazoles are aromatic compounds but less so than the thiazoles. Oxazole is a weak base; its conjugate acid has a pKa of 0.8, compared to 7 for imidazole.