It is reported for the first time that iodine-doped reduced graphene oxide (I-rGO) has been designed as an anode material for sodium ion batteries (SIBs). In comparison to rGO, I-rGO with a high specific surface area exhibits a high reversible capacity (270 mA h g⁻¹ at 50 mA g⁻¹), good long-term cycling performance, with a high capacity of 212 mA h g⁻¹ after 100 cycles, and excellent rate capability. The enhanced performance is due to defect evolution and enlarged layer distance by the doping of iodine atoms.