To meet the requirement of fuel cells and metal–air batteries, non‐noble metal catalysts have to be developed to replace precious platinum‐based catalysts. Herein, Co nanoclusters (≈2 nm) are anchored on nitrogen‐doped reduced graphene oxide (Co/N‐r‐GO) by using DUT‐58 (Co) metal–organic framework and GO as precursors. Compared with single‐atom catalysts usually with ultralow concentration (<0.5 wt%), Co nanoclusters are more beneficial to break the OO bond to ensure four electronic way for oxygen reduction reaction (ORR), since they can provide more adsorption centers for reactants. Therefore, as expected, the sample with 6.67 wt% Co content (Co/N‐r‐GO‐5%‐850) exhibits better ORR activity with a higher half‐wave potential of 0.831 V, a more positive onset potential of 0.921 V than Pt/C, and a comparable limiting current density in alkaline medium. The Co nanoclusters enhance the catalytic performance for ORR in three aspects: quantum size effects, metal–support interactions, and low‐coordination environment of metal centers. Furthermore, the sample is assembled into a zinc–air battery as the outstanding durable ORR catalyst. It displays a higher specific capacity (795 mAh g−1 at the current density 50 mA cm−2) and power density (175 mW cm−2) than Pt/C (731 mAh g−1 and 164 mW cm−2, respectively).