甲硫醇又被称为巯基甲烷、硫氢甲烷，分子式：CH₃-SH，分子量：48.10，CAS号：74-93-1。常温常压下为无色气体，有烂白菜气味，因此常被加进煤气中。它是一个具有独特腐臭气味的无色气体。它在人类的血液和脑中发现的天然物质，以及其他动物以及植物组织中。它是通过动物的粪便排弃。它天然存在于某些食品，如一些坚果和奶酪。它也是口臭和屁的气味的主要化合物之一。它是易燃的。

甲硫醇主要用于生产甲硫氨酸，其被用在家禽和动物饲料膳食的成分。甲硫醇也用于在塑料工业中用作自由基聚合的调节剂的和作为生产杀虫剂中的前体。甲硫醇也用于在采矿作业时的通信。

Methanethiol /ˈmɛθeɪnˈθaɪɒl/ (also known as methyl mercaptan) is an organosulfur compound with the chemical formula CH
3SH. It is a colorless gas with a distinctive putrid smell. It is a natural substance found in the blood and brain of humans and other animals as well as plant tissues. It is disposed of through animal feces. It occurs naturally in certain foods, such as some nuts and cheese. It is also one of the main compounds responsible for bad breath and the smell of flatus. Methanethiol is classified as a thiol and is sometimes abbreviated as MeSH. It is very flammable.