In this study, a heterogeneous catalyst based on copper nanoparticles immobilized on metal oxide, WO3, was fabricated using an impregnation method as an easy and straightforward nanoparticle synthesis strategy. The successful synthesis of the nanocatalyst was confirmed using various spectroscopic techniques such as X‐ray diffraction, scanning electron microscopy, energy dispersive X‐ray analysis, and transmission electron microscopy. The catalytic performance of the well‐characterized material was evaluated through the azide–alkyne cycloaddition reaction (click reaction) in the aqueous medium. To optimize reaction conditions, different reaction parameters such as nanocatalyst amount, reaction time, temperature, and solvents were studied. Experimental results showed that as‐prepared nanocatalyst (Cu/WO3) could act as an effective and reusable heterogeneous catalyst in water for the synthesis of 1,2,3‐triazoles in good‐to‐excellent yields. In addition, Cu/WO3 has some advantages such as simple preparation procedure, easy separation, and recyclability for three runs with no remarkable loss of catalytic activity, which is essential from a catalytic application point of view.