In this paper, a novel electrochemical sensor based on a functionalized multi-walled carbon nanotube (f-MWCNT) decorated ruskin michelle-like zinc oxide (ZnO) nanocomposite for the determination of the environmental pollutant hydroquinone (HQ) is reported. We have followed a new aqueous solution method for the synthesis of ruskin michelle-like ZnO nanoparticles and they are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and UV visible spectroscopy. Cyclic voltammetry (CV), differential pulse voltammetry (DPV) and amperometric techniques are used for the electrochemical analysis of a f-MWCNT decorated ruskin michelle-like ZnO nanocomposite modified glassy carbon electrode (GCE). The fabricated f-MWCNT/ZnO GCE showcased excellent electrocatalytic activity in the determination of HQ and we obtained a sharp anodic and cathodic peak current at a low potential value of 0.11 V and 0.05 V, respectively. Efficient reproducibility and stability, anti-interference property and good repeatability, which are the traits of a good electrochemical sensor, are exhibited by the fabricated sensor. We have obtained a very low limit of detection (LOD) for the fabricated f-MWCNT/ZnO GCE of 0.02 μM, a linear response in the range of 0.1–190 μM and a sensitivity of 6.37 μA μM⁻¹ cm⁻². These results obtained from the electrochemical analysis reveal the excellent performance of the f-MWCNT decorated ruskin michelle-like ZnO nanocomposite modified GCE in the effective determination of HQ.