Nonvolatile bipolar resistive switching has been investigated in Mn-doped BiFeO₃ thin films fabricated by sol–gel method. Based on the analyses of X-ray diffractometer and X-ray photoelectron spectroscopy, the threshold voltages for forming and set operations in bipolar resistive switching, which are found to depend on Mn doping concentration and annealing temperature, can be ascribed to the variation of oxygen vacancy concentration and grain size. Therefore, the modulated ionic oxygen vacancy conductivity has been suggested to play a pivotal role in the resistive switching of Mn-doped BiFeO₃ thin films.