Abstract The use of ubiquities elements such as iron instead of expensive precious metals as catalysts is one goal toward realizing environmentally benign synthetic chemistry. Here, we report that porous FeO(OH) dispersed on Mg−Al hydrotalcite acts as a bifunctional heterogeneous catalyst in the one‐pot synthesis of 2‐substituted quinoline derivatives through dehydrogenative oxidation‐cyclization reactions. The catalyst was prepared by a simple grafting method using FeCl 3 and Mg−Al hydrotalcite. The prepared porous FeO(OH) possesses a higher surface area than those previously reported for α‐FeO(OH) particles. The one‐pot quinoline synthesis proceeded effectively under non‐noble‐metal catalysis in air without requiring additional homogeneous bases or solvents.