Yttrium(III) bromide is an inorganic compound with the chemical formula YBr<sub>3</sub>. It is a white solid. Anhydrous yttrium(III) bromide can be produced by reacting yttrium oxide or yttrium(III) bromide hydrate and ammonium bromide. The reaction proceeds via the intermediate (NH<sub>4</sub>)<sub>3</sub>YBr<sub>6</sub>. Another method is to react yttrium carbide (YC<sub>2</sub>) and elemental bromine. Yttrium(III) bromide can be reduced by yttrium metal to YBr or Y<sub>2</sub>Br<sub>3</sub>. It can react with osmium to produce Y<sub>4</sub>Br<sub>4</sub>Os.