An effective electrochemical sensor based on electrodeposition of nickel selenide nanoparticles (Ni3Se4) on the surface of a glass carbon electrode (GCE) modified with hydroxylated multiwalled carbon nanotubes (MWCNTs-OH) has been successfully developed for determination of maltol. The chemical composition and morphology of Ni3Se4/MWCNTs-OH composites are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) are employed to investigate the electrochemical behavior of maltol at Ni3Se4/MWCNTs-OH/GCE. Consequently, electrochemical sensor based on Ni3Se4/MWCNTs-OH/GCE for detection of maltol displays good electrocatalyst performance. The obtained oxidation peak current of maltol at Ni3Se4/MWCNTs-OH/GCE increases linearly with the increase in concentration of maltol in the range of 0.1 μM–2000 μM, and the calculated detection limit (LOD) is 17.5 nM (S/N = 3). In addition, the fabricated electrochemical sensor shows satisfactory stability, reliable reproducibility and excellent selectivity, and is successfully used to detect maltol in real samples with acceptable accuracy.