This paper reports a novel graphene (G)/zirconium dioxide (ZrO2) nanocomposite produced using a sol-gel method with various weight percentages of graphene for use in humidity sensors. The morphological and structural properties of the (G/ZrO2) were characterized using X-ray diffraction (XRD) , Fourier transform infrared (FTIR), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). The response characteristics of the sensor, including sensitivity, hysteresis, response time, and recovery time, were investigated from theoretical as well as experimental perspectives. Experimental results revealed a linear functional relationship between shifts in the impedance of the sensor and variations in relative humidity. The sensor with 40 wt% G/ZrO2 nanocomposite demonstrated a sensitivity (S = 4011) exceeding that of the other samples. At all humidity levels, the humidity hysteresis values remained low, and the response and recovery times were very rapid (5 and 20 s, respectively). These results demonstrate the considerable potential of using G/ZrO2 nanocomposites in the further development of humidity sensors.