Osmium tetrabromide is the inorganic compound with the formula OsBr4.

A black solid, this compound can be produced by heating osmium tetrachloride and bromine under pressure.

As determined by X-ray crystallography, osmium tetrabromide is an inorganic polymer.

It is isomorphous with platinum tetrabromide and technetium tetrachloride.

Each osmium center bonds to four doubly bridging bromide ligands and two mutually cis terminal bromide ligands.