Iron(III) azide, also called ferric azide, is a chemical compound with the formula Fe(N3)3.

It is an extremely explosive, impact-sensitive, hygroscopic dark brown solid.

This compound is used to prepare various azidoalkanes, such as n-butyl azide, from alkenes via formation of alkylboranes and subsequent anti-Markovnikov addition of azide group.

[2] This compound is prepared by the reaction of sodium azide and iron(III) sulfate in methanol:[2] Iron(III) azide can also be formed by pulse gamma-irradiation of a mixture of iron(II) perchlorate, sodium azide, and hydrogen peroxide.

[3] Under these conditions, a neutral N3 radical is formed, which oxidizes the iron(II) to iron(III); the iron(III) then promptly combines with azide ions.