二氯化二硫，有时亦作一氯化硫，化学式S₂Cl₂。

二氯化二硫是一种黄红色液体，有刺激性、窒息性恶臭，在空气中强烈发烟。遇水分解为硫、二氧化硫、氯化氢。溶于醚、苯、二硫化碳。室温下稳定，100°C时分解为相应单质，300°C时则完全分解。

能被金属还原为氯化物和硫化物。与氯气反应生成二氯化硫。能与金属氧化物或硫化物反应生成金属氯化物。

Disulfur dichloride is the chemical compound of sulfur and chlorine with the formula S₂Cl₂.

Some alternative names for this compound are sulfur monochloride (the name implied by its empirical formula, SCl), disulphur dichloride (British English Spelling) and sulphur monochloride (British English Spelling). S₂Cl₂ has the structure implied by the formula Cl-S-S-Cl, wherein the angle between the Cl-S-S and S-S-Cl planes is 90°. This structure is referred to as gauche, and is akin to that for H₂O₂. A different isomer of S₂Cl₂ is S=SCl₂; this isomer forms transiently when S₂Cl₂ is exposed to UV-radiation (see thiosulfoxides).