Four organic–inorganic hybrid ionic liquid polyoxometalate (IL–POM) nanomaterials which combined excellent electrochemical properties of ILs and POMs have been fabricated by a facile synthesis method of solid-state chemical reaction at room temperature with the reactants of four ILs and Keggin-type structure phosphomolybdic acid. The electrochemical studies reveal that the as-prepared IL–POM modified carbon paste electrodes (IL–POM CPEs) show enhanced electrochemical responses than those of quaternary ammonium polyoxometalates, which may be due to the conductivities of the organic cations for ILs. Furthermore, IL–POM CPEs exhibit good catalytic activities and sensitive responses to the reduction of nitrite, bromate and hydrogen peroxide. Owing to its outstanding performance, the organic–inorganic hybrid IL–POM CPEs would take on promising prospects of the practical applications in electrochemical sensors.