喹啉，也叫做苯并吡啶、氮杂萘，是一个杂环芳香性有机化合物。喹啉是一个具有强烈臭味的无色吸湿性液体，分子式是C₉H₇N。

将喹啉暴露在光下，会慢慢变成淡黄色，进一步变成棕色。喹啉微溶于水，但是易溶于很多有机溶剂。

喹啉是冶金、染料、聚合物以及农用化学品工业的重要中间体。它也可以用作消毒剂、防腐剂以及溶剂。

喹啉是有毒性的，短时间暴露在喹啉蒸汽中会导致鼻子、眼睛和呼吸道被腐蚀，也可能导致头昏和恶心。长时间暴露的影响还不确定，不过喹啉与肝损伤有一定的关系。

Quinoline is a heterocyclic aromatic organic compound with the chemical formula C₉H₇N. It is a colorless hygroscopic liquid with a strong odor. Aged samples, especially if exposed to light, become yellow and later brown. Quinoline is only slightly soluble in cold water but dissolves readily in hot water and most organic solvents. Quinoline itself has few applications, but many of its derivatives are useful in diverse applications. A prominent example is quinine, an alkaloid found in plants. 4-Hydroxy-2-alkylquinolines (HAQs) are involved in antibiotic resistance.