Spinel FeMn_xCo_2-xO₄ (x = 0, 0.1, 0.2 and 0.4) nanofibers were successfully synthesized by electrospinning technique. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and FESEM, techniques were used to characterize phase, oxidation states, and morphology of synthesized materials. Magnetic properties of materials were inverstigated using vibrating sample magnetometer (VSM). At room temperature, ferromagnetic character was shown by all the samples and maximum saturated magnetization (32 emu g⁻¹) obtained for x = 0.4 sample. To study the electrical transport with and without magnetic field. A detailed transport analysis of FeMn_xCo_2-xO₄ (x = 0, 0.1, 0.2 and 0.4) nanofibers are carried out where highest conductivity (2.08×10⁻⁵ S cm⁻¹) was obtained for x = 0.2. This may be because of higher interfacial area or grain boundaries that may acting as short-circuiting pathways for easy ionic movement. However, under magnetic environment, conductivity of x = 0.4 samples is increased by almost two times, justifying the importance of this material in magnetoelectric applications. Furthermore, magnetic field driven supercapacitive storage analysis was also performed under small magnetic field of 3 mT. A huge increment in capacitance value form 191 F g⁻¹ to 308 F g⁻¹ is observed for x = 0.4 sample. Magnetic and electrical properties of Mn-doped FeCo₂O₄ have been found crucial to alter the supercapacitive properties. This study is unraveling a new tactic for improving the energy storage properties of a given material.