AbstractTransition metal oxides with high specific capacities and variable electronic structures are of paramount importance for advanced energy conversion and storage, yet suffering from low electronic conductivity and poor structural stability during the electrochemical process. Herein, via direct laser printing on an Mn‐based metal–organic framework (Mn‐MOF) in air, MnO/Mn3O4 nanoparticles confined in mesoporous graphitic carbon can be mass‐produced rapidly. It is revealed that the structural transformations in manganese oxides (MnOx → Mn3O4 → MnO) occur during the decomposition of the Mn‐MOF and the MnO/Mn3O4 nanoparticles promote the catalytic graphitization of disordered carbon. The composite shows high electrocatalytic oxygen evolution reaction performances in the alkaline electrolyte with an overpotential of 394 mV at 10 mA cm−2 and good durability of 75% retention after 24 h. In addition, it also exhibits promising supercapacitive performances with a specific capacitance of 194 F g−1 and reasonable stability of 82% retention after 5000 cycles.