Californium(III) bromide is an inorganic compound, a salt with a chemical formula CfBr<sub>3</sub>. Like in californium(III) oxide (Cf<sub>2</sub>O<sub>3</sub>) and other californium halides, including californium(III) fluoride (CfF<sub>3</sub>), californium(III) chloride, and californium(III) iodide (CfI<sub>3</sub>), the californium atom has an oxidation state of +3.
Californium(III) bromide is shown to crystallize in both the AlCl<sub>3</sub> and FeCl<sub>3</sub> type structures. In the former structure, the californium ion is six coordinated and the three independent Cf-Br bond lengths are 279.5ñ0.9 pm, 282.7ñ1.1 pm, and 282.8ñ0.8 pm.
Californium(III) bromide partially decomposes into californium(II) bromide under high temperature.
In the radioactive decay of berkelium-249 to californium-249, the oxidation number and crystal structure are preserved. The six-coordinate berkelium(III) bromide (AlCl<sub>3</sub>-type monoclinic structure) decays to produce a six-coordinate californium(III) bromide, whereas an eight-coordinate berkelium(III) bromide (PuBr<sub>3</sub>-type, orthorhombic structure) produces an eight-coordinate californium(III) bromide.