Thiazole, also known as 1,3-thiazole, is a type of heterocyclic compound that includes both nitrogen and sulfur atoms. It has a molecular formula of C3H3NS and is a pale yellow liquid possessing a scent reminiscent of pyridine.

There are multiple laboratory techniques available for the organic synthesis of thiazoles, with the most notable being the Hantzsch thiazole synthesis, which involves a reaction between haloketones and thioamides.

Thiazole rings exhibit planarity and aromaticity, with more extensive pi-electron delocalization than their oxazole counterparts, resulting in greater aromaticity for thiazoles.

Thiazoles find applications in peptide research and serve as a fundamental component in biologically active natural products such as thiamine (vitamin B1), bacitracin, and the penicillins, as well as in a wide range of synthetic drugs, dyes, and industrial chemicals.