The oxygen reduction reaction (ORR) is a critical factor in fuel cells that has attracted significant research attention. Non-precious metal catalysts have improved the ORR activity considerably, but they still exhibit poorer ORR performance than commercial Pt-based catalysts. In this study, Co-N₄-doped mesoporous carbon (Co-N₄-MC) was prepared for the ORR using cobalt-azides as the Co-N₄-containing precursor, and ordered mesoporous silica SBA-15 as a template for achieving mesoporous structures. The Co-N₄-MC electrode exhibited remarkable ORR activity in an alkaline medium (a half-wave potential of −0.15 V vs. MMO, only ~19 mV deviation from the commercial Pt/C catalyst), high selectivity (electron-transfer number ~4) and excellent electrochemical stability (~8 mV negative shift of the half-wave potential after 1000 cycles). The good performance of the Co-N₄-MC electrode was attributed to the synergetic effects of N₄, C and Co. In particular, the existence of graphitic pores in the Co-N₄-MC catalyst facilitated the diffusion of O₂ to the catalytic active sites, which benefited the progression of the ORR on the Co-N₄-MC catalyst.