Disulfur dibromide is the inorganic compound with the formula S2Br2. It is a yellow-brown liquid that fumes in air. It is prepared by direct combination of the elements and purified by vacuum distillation. Higher yields can be obtained from disulfur dichloride and 50% aqueous hydrobromic acid, but the product must be promptly removed from water, lest it hydrolyze. The compound has no particular application,[citation needed] unlike the related sulfur compound disulfur dichloride, although acidic alcoholysis is "an excellent synthesis of alkyl bromides."

The molecular structure is Br−S−S−Br, akin to that of disulfur dichloride (S2Cl2). According to electron diffraction measurements, the angle between the Bra−S−S and S−S−Brb planes is 84° and the Br−S−S angle is 107°. The S−S distance is 198.0 pm, circa 5.0 pm shorter than for S2Cl2.