Thulium(II) iodide is an inorganic compound with the chemical formula TmI2.

Thulium(II) iodide can be obtained by reacting thulium(III) iodide and alkali metals in a tantalum container at 700~800°C.

TmI2 can be obtained by using lithium and sodium as reducing agents, while potassium, rubidium and caesium can generate the perovskite structure MTmI3.

[2] TmI2 can also react directly with CsI (340 °C) to generate CsTmI3.

[3] Thulium(II) iodide can also be prepared by reacting thulium and mercury(I) iodide.