Hydroquinone (HQ) is a toxic and poorly biodegradable substance that can cause various health issues. To address this problem, we devised an electrochemical sensor using Ce2(WO4)3@rGO (CeW@rGO) nanocomposites coated onto a glassy carbon electrode (GCE). The novel nanocomposites were synthesized using a hydrothermal process, with varying reaction times of 2, 6, 12, 24, and 48 h. It was then treated with a surfactant and combined with reduced graphene oxide (rGO) to produce CeW@rGO nanocomposite. The GCE was then modified using different CeW-X (where X represents the reaction times of 2, 6, 12, 24, and 48 h). Among these, the CeW-6@rGO nanocomposite exhibited the most optimal electrochemical behavior. Our results showed that the novel sensor made with CeW-6@rGO nanocomposites possesses long-term stability with high selectivity for sensing HQ. The new CeW-6@rGO/GCE sensor has a detection limit of 0.00964 μM with a linear range of 0.1–115 µM and can detect HQ in real-world water samples with reliable results. Our findings suggest that this novel sensor is potentially useful in real-world applications.