Transition metal oxides are attractive as anode materials in lithium-ion batteries for their high theoretical capacity and good performance. In this work, an anode material based on manganese-based oxide FeMnO3 in LIBs is investigated for the first time. FeMnO3 is prepared with graphene and the FeMnO3/graphene composite exhibits a high discharge capacity of 1155.3 mAh g−1 after 300 cycles at 200 mA g−1, as well as a superior rate performance of 851.7 mAh g−1 at a current density of 3200 mA g−1. The observed extraordinary performance is believed to be attributed to the combination of the intrinsically high capacity of FeMnO3, a large surface area of 89.65 m2 g−1 and good electrical conductivity of the FeMnO3/graphene composite. To help clarify the properties of this new material, we employ first principles calculations to determine the structural stability, electronic structure, and Li ion diffusivity of FeMnO3. The calculations show that FeMnO3 has a relatively low band gap (an indication of reasonable electrical conductivity) and Li ions exhibit a large room temperature diffusivity in FeMnO3.