Recently, precious metal-free and heteroatom functionalized carbon materials are widely considered as the promising candidates for oxygen reduction reaction (ORR). However, it is still a challenge to controllably prepare the carbon-based electrocatalysts with desirable activities. Herein, we demonstrate a simple strategy to synthesize the Fe/S/N tri-doped mesoporous carbon (Fe-S,N-C) materials as electrocatalysts for ORR. The resultant Fe-S,N-C catalyst possesses high content of pyridinic N (also including Fe-Nx), graphitic N atoms, thiophene S atoms, and abundant defects, as well as the high surface area and desirable mesoporous microstructure. Thus, in alkaline medium, the Fe-S,N-C shows an expected high ORR activity with a onset potential of 0.95 V and half-wave potential of 0.83 V. Meanwhile, the ORR proceeded on Fe-S,N-C via the four-electron transfer pathway. What is more, the as-prepared catalyst shows excellent electrocatalytic stability and good methanol tolerance, suggesting its potential applications in fuel cells and metal-air battery. Graphical AbstractA high-performance Fe/S/N tri-doped mesoporous carbon-based electrocatalyst with abundant defects and active sites has been successfully prepared by one easy way for ORR in alkaline medium.