Noncovalent functionalization of graphene with iron tetrasulfophthalocyanine (FeTsPc) is achieved not only to prevent the aggregation of graphene but also form an efficient electrocatalyst for the oxygen reduction reaction (ORR) in a dual-chamber microbial fuel cell (MFC). The electrochemical activity of the FeTsPc-functionalized graphene (FeTsPc-graphene) is evaluated towards the ORR using cyclic voltammogram (CV) and linear sweep voltammogram (LSV) methods. More positive peak potential and larger peak current of ORR are found using FeTsPc-graphene electrode as compared to FeTsPc electrode, suggesting enhanced activity of FeTsPc after adsorbing on graphene surface. The maximum power density of 817mWm−2 obtained from the MFC with a FeTsPc-graphene cathode is higher than that of 523mWm−2 with a FeTsPc cathode and is close to that of 856mWm−2 with a Pt/C cathode. Thus, FeTsPc-graphene nanocomposites can be a good alternative to Pt catalyst in MFCs.