Reported herein is the first visible‐light‐induced formation of alkoxyl radicalsfrom N‐alkoxyphthalimides, and the Hantzsch ester as the reductant is crucial for the reaction. The selective hydrogen atom abstraction by the alkoxyl radical enables C(sp3)−H allylation and alkenylation reactions under mild reaction conditions at room temperature. Broad substrate variations, including a structurally complexed