二甲基硫醚，是最简单的硫醚化合物。结构、性质与二甲基醚类似。常温下为无色挥发性液态。有着如海鲜般特殊气味物质。在自然界中，常由蛋白质的分解产生。这也是海鲜腥味的来源之一。

无色透明有不愉快气味的液体，易燃、易挥发。高毒。不溶于水，溶于乙醇、乙醚。

Dimethyl sulfide (DMS) or methylthiomethane is an organosulfur compound with the formula (CH₃)₂S. Dimethyl sulfide is a water-insoluble flammable liquid that boils at 37 °C (99 °F) and has a characteristic disagreeable odor. It is a component of the smell produced from cooking of certain vegetables, notably maize, cabbage, beetroot and seafoods. It is also an indication of bacterial contamination in malt production and brewing. It is a breakdown product of dimethylsulfoniopropionate (DMSP), and is also produced by the bacterial metabolism of methanethiol.