Magnetic materials/ZnO hybrid nanostructures have been extensively studied due to their improved absorption properties in photocatalytic applications and their potential for application in an external magnetic-field-controlled photodevice. However, how the optical properties are modified by coating magnetic materials in hybrid nanostructures remains unclear. Here, we report a tunable magnetoabsorption (MA) effect in Co-coated ZnO nanowires with Au decoration. Using Au decoration, we revealed a transformation behavior that enables the tunability of a sizeable MA from the negative to positive ratio through magnetoplasmonic effect induced electron transfer at the interface between Au and Co coated ZnO nanowires. The appealing physical properties revealed in this study indicate the possibility of manipulating the MA of transition metal-coated oxide nanostructures.