Lanthanum diiodide is an iodide of lanthanum, with the chemical formula of LaI2.

It is an electride, actually having a chemical formula of La3+[(I−)2e−].

[2] Lanthanum diiodide can be obtained from the reduction of lanthanum(III) iodide with lanthanum metal under a vacuum at 800 to 900 °C:[3] It can also be obtained by reacting lanthanum and mercury(II) iodide:[3] It was first created by John D. Corbett in 1961.

[4] Lanthanum diiodide is a blue-black solid with metallic lustre, which is easily hydrolyzed into the iodide oxide.

[3] It has a MoSi2-type structure, with the space group I4/mmm (No.