Highly efficient and non-precious catalysts are imperative for oxygen reduction reaction (ORR) to replace Pt/C. Anchoring efficient active species to carbon supports is a promising and scalable strategy. Here we synthesize Cu nanoparticles and noncrystalline CuN x C y species co-decorated ketjenblack (KB) carbon catalyst (denoted as Cu-N-KB-acid) by a facile and scalable method using copper sulfate, melamine, and KB as raw materials. An initial one-pot hydrothermal treatment is designed before pyrolysis process to achieve the good distribution of Cu and melamine on KB via a possible chelation effect. Owing to the synergistic effect of Cu and CuN x C y on KB, this composite catalyst displays excellent ORR catalytic activity in alkaline solution, which is comparable to the commercial 20% Pt/C. When used as a catalyst in a home-made Al–air battery, it shows a stable discharge voltage of 1.47 V at a discharge density of 50 mA cm−2, a little higher than that of Pt/C (1.45 V).