Gallane, also systematically named trihydridogallium, is an inorganic compound of gallium with the chemical formula GaH3 (also written as [GaH3]).

It has been detected as a transient species in the gas phase;[2] also at low temperature (3.5 K) following the reaction of laser ablated gallium atoms and dihydrogen, and more recently in an argon matrix doped with vapour over solid digallane, Ga2H6.

[5] As GaH3 cannot be prepared or isolated readily reactions involving GaH3 either use the dimer, Ga2H6, digallane(6) or adducts of GaH3 for example L·GaH3 where L is a monodentate ligand.

Also whilst N donor ligands form stronger bonds to alumane than phosphines the reverse is typically true for gallane.

[8][verification needed] Upon treatment with a standard base, it converts to a metal tetrahydroxygallanuide (the anion Ga(OH)4−) and hydrogen gas.