An eco-friendly synthesis of heteroatom-enriched activated carbon (HAC)-nickel oxide (NiO) nanocomposites invoking a simple electrochemical strategy is reported. The structure and surface properties of the synthesized HAC/NiO materials were characterized by a variety of different analytical and spectroscopic techniques, viz. elemental and thermal analyses, physisorption, X-ray diffraction, Raman spectroscopy, field emission-scanning and transmission electron microscopy, and X-ray photoelectron spectroscopy. The electrochemical properties were probed by cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. The HAC/NiO-modified electrodes exhibited remarkable sensitivity (1722μAμM−1cm−2) and excellent detection limit (55nM) for detection of glucose with desirable selectivity, stability, reproducibility, and tolerance to interference, even for practical analysis of real samples. The unique properties and remarkable electrochemical performances possessed by such facilely prepared HAC/NiO nanocomposite materials render their prospective applications as cost-effective, non-enzymatic glucose sensors.