Einsteinium triiodide is an iodide of the synthetic actinide einsteinium which has the molecular formula EsI3.

This crystalline salt is an amber-coloured solid.

[1] It glows red in the dark due to einsteinium's intense radioactivity.

It crystallises in the hexagonal crystal system in the space group R3 with the lattice parameters a = 753 pm and c = 2084.5 pm with six formula units per unit cell.

Its crystal structure is isotypic with that of bismuth(III) iodide.