Ga2O3-based gas sensors are known to show very poor performance at room temperature even though recent studies on Ga2O3 thin film-based gas sensors demonstrated that they detected O2, H2, CO, and CH4 gases efficiently at high temperatures of 600–1000 °C. This high working temperature limits the practical usage of Ga2O3-based gas sensors. In this study, the NO2 gas sensing properties of multiple-networked Pd-doped Ga2O3 nanowire sensors were examined. Scanning electron microscopy showed nanowires with diameters of 50–100 nm and lengths of a few micrometers. Transmission electron microscopy and X-ray diffraction showed that the nanowires were monoclinic single-crystal Ga2O3. The Pd-doped Ga2O3 nanowire sensors showed far enhanced sensing performance to NO2 gas at room temperature compared to bare-Ga2O3 nanowire sensors. No appreciable dynamic sensing behaviors were observed for bare-Ga2O3 nanowire sensors at room temperature. In contrast, the sensors showed sensitivities of 26.86, 30.19, and 41.44% at NO2 concentrations of 10, 50, and 100 ppm, respectively. In addition, the origin of the enhancement of the sensing properties of the Ga2O3 nanowires by Pd doping is discussed.