Ammonium azide is the chemical compound with the formula [NH4]N3, being the salt of ammonia and hydrazoic acid.

Like other inorganic azides, this colourless crystalline salt is a powerful explosive, although it has a remarkably low sensitivity.

[NH4]N3 is physiologically active and inhalation of small amounts causes headaches and palpitations.

Ammonium azide is ionic, meaning it is a salt consisting of ammonium cations [NH4]+ and azide anions N−3, therefore its formula is [NH4]+[N3]−.

Ammonium azide contains about 93% nitrogen by mass.