•Novel β-nickel molybdate (β-NiMoO4) nanosheets were synthesized by a microwave-assisted solvothermal method.•The as-prepared NiMoO4 nanosheets exhibited strong absorption property for electroactive ferricyanide ion and graphite.•NiMoO4 nanosheets provided a potential catalytic platform for NADH and ethanol sensing. Novel β-nickel molybdate (β-NiMoO4) nanosheets were synthesized by a microwave-assisted solvothermal method, and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), high-resolution TEM (HRTEM), and energy dispersive spectrum (EDS). The as-prepared NiMoO4 nanosheets exhibited strong absorption property for electroactive ferricyanide ion (Fe(CN)63−) and graphite, allowing their easy and stable modification on carbon paste electrode (CPE), which was demonstrated good electrocatalytic activity toward the oxidation of β-nicotinamide adenine dinucleotide (NADH). In addition, a nonenzymatic ethanol sensor based on NiMoO4 nanosheets was also first presented in this work.