Thallane (systematically named trihydridothallium) is an inorganic compound with the empirical chemical formula TlH3.

Thallanes have been observed only in matrix isolation studies; the infrared spectrum was obtained in the gas phase by laser ablation of thallium in the presence of hydrogen gas.

[2] This study confirmed aspects of ab initio calculations conducted by Schwerdtfeger which indicated the similar stability of thallium and indiganes.

In 2004, American chemist Lester Andrews synthesised thallane for the first time.

This reaction sequence consisted of atomisation of thallium, followed by cryogenic co-deposition with hydrogen, and concluded with shortwave ultraviolet irradiation.