Californium(III) iodide is a binary inorganic compound of californium and iodine with the formula .
Californium triiodide can be prepared in microgram quantities under high vacuum. It can be prepared at 500 ðC from californium(III) hydroxide and hydrogen iodide:
The compound forms a red-orange solid. The triiodide sublimes at ~800 ðC without melting. It crystallizes in the trigonal crystal structure in the space group R3 (No. 148) with the lattice parameters a = 758.7 pm and c = 2081.4 pm with six formula units per unit cell. Its crystal structure is isotypic with that of bismuth(III) iodide.