Molybdenum(III) bromide is the inorganic compound with the formula MoBr3.

[1] It can also be prepared from the reduction of molybdenum(IV) bromide with molybdenum metal, hydrogen gas, or a hydrocarbon.

[2] It has a structure consisting of infinite chains of face-sharing octahedra with alternatingly short and long Mo-Mo contacts.

The same structure is adopted by the tribromides of ruthenium and technetium.

[3][4] In contrast, in the high temperature phase of titanium(III) iodide, the Ti---Ti separation is invariant.