The development of cost-effective electrode materials that can combine energy storage and electrocatalytic functionalities is essential for future sustainable energy systems. This study involves the synthesis of a trimetallic Nickel based nanocomposite by a low-temperature hydrothermal method, subsequently accompanied by moderate calcination. The structural and morphological analysis verifies the development of a nanocrystalline porous architecture conducive to electrochemical applications. Electrochemical assessment demonstrates that it displays outstanding multifunctional capabilities. In 2M KOH, it functions as a supercapacitor electrode, exhibiting a specific capacitance of 1175 F/g at 1 A g⁻¹, with a capacitance retention of 92.59% after 4000 cycles. Furthermore, it exhibits significant electrocatalytic efficacy for water splitting, necessitating an overpotential of 180 mV to achieve 10 mA cm⁻² for the oxygen evolution reaction in 2 M KOH and approximately 370 mV for the hydrogen evolution reaction in 0.5 M H₂SO₄, while maintaining stable long-term performance. The results suggest that this nanocomposite is a viable non-noble electrode material for integrated electrochemical energy storage and water-splitting applications.