We report herein an unprecedented combination of light and P(III)/P(V) redox cycling for the efficient deoxygenation of aromatic amine N‐oxides. Moreover, we discovered that a large variety of aliphatic amine N‐oxides can easily be deoxygenated by using only phenylsilane. These practically simple approaches proceed well under metal‐free conditions, tolerate many functionalities and are highly chemoselective. Combined experimental and computational studies enabled a deep understanding of factors controlling the reactivity of both aromatic and aliphatic amine N‐oxides.