The development of a novel material with excellent properties for energy storage and sensors has been considered the best material to overcome the future energy demand and economic crisis. Herein, a three-dimensional (3D) hybrid nanocomposite (3D-CeVO₄/MWNT HNC) was fabricated based on; i) synthesis of cerium vanadate nanoparticles (CeVO₄ NPs) through simple precipitation, and ii) successful inclusion of CeVO₄ NPs on multiwall carbon nanotube (MWNT) by using ultrasonication approach. To reveal the physicochemical parameters of 3D-CeVO₄/MWNT HNC, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffraction (P-XRD), field emission-scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), and electrochemical techniques are utilized. As synthesized 3D-HNC possessed the specific features of both CeVO₄ NPs and MWNT exhibits high electrocatalytic behavior due to its high surface area and conductivity. It has been more attractive for the application of energy storage and as an electrochemical sensor. 3D-CeVO₄/MWNT HNC reveals high specific capacity value of 378 C g⁻¹ at 1 A g⁻¹ with long cycle life with 90.8% retention. Also, the proposed sensor shows a low detection limit of 0.07 μM and sensitivity of 20.71 µA µM⁻¹ cm⁻² with a dynamic linear range of 2-322.5 μM. Then the resulting sensor was also applied to detect the L-Trp in the real-time sample. Hence 3D-CeVO₄/MWNT HNC could be a promising material for both applications of the electrochemical sensor and supercapacitor.