A resistive random access memory (RRAM) includes a resistive memory layer of a transition metal oxide, such as Ni oxide, and is doped with a metal material. The RRAM may include at least one first electrode, a resistive memory layer on the at least one first electrode, the resistive memory layer including a Ni oxide layer doped with at least one element selected from a group consisting of Fe, Co, and Sn, and at least one second electrode on the resistive memory layer. The RRAM device may include a plurality of first electrodes and a plurality of second electrodes, and the resistive memory layer may be between the plurality of first electrodes and the plurality of second electrodes.