Nowadays, the ternary nanocomposites based electrode materials have been greatly investigated due to their unique properties of multiple oxidation states, excellent stability, and the enhanced electrochemical activities in energy storage applications. In this study, we prepare ternary Ni-Mn-Zn Oxide nanocomposites through an inexpensive one pot hydrothermal technique. The obtained nanocomposites were further characterized by XRD, FTIR, FESEM, EDX, HR-TEM, and SAED analysis. The ternary Ni-Mn-Zn Oxide electrode manifests a higher specific capacitance of 1311.00 F/g compared to binary NiMn2O4 (255.16 F/g) and ZnMn2O4 (498.00 F/g) nanocomposites at the scan rate of 10 mV/s. Additionally, the ternary electrode exhibits 718.37, 1575.61, and 857.23 F/g of outer, total, and inner specific capacitances from Trasatti analysis, and provides 54.40 % and 45.59 % of capacitive and diffusion contribution percentages. The Ni-Mn-Zn Oxide//AC hybrid supercapacitor device has been constructed and reveals an excellent energy density of 23.64 Wh kg-1 and a higher power density of 6499.79 W kg � 1. Also, it delivers a good capacitive retention of 51.81 % and coulombic efficiency (& eta;%) of 100.48 % for 20,000 charge/discharge cycles.