To achieve high⁃performance, low⁃cost zinc oxide (ZnO)⁃based ultraviolet photodetectors, utilizing Ga⁃doped ZnO (ZnO:Ga) as the photosensitive layer is key. This study synthesized ZnO:Ga microrods with varying Ga doping concentrations (0% [undoped ZnO], 0.5%, 1%, 2%, and 4%) using a straightforward hydrothermal method. The atomic ratios of Ga to Zn were meticulously adjusted. Initial analyses revealed that all samples possessed the hexagonal wurtzite ZnO structure, as confirmed by X⁃ray diffractometry (XRD). Scanning electron microscopy (SEM) showed that the microrods maintained a consistent rod⁃like morphology. Subsequently, these microrods were applied to fluorine⁃doped tin oxide (FTO) glass substrates with interdigital patterns to construct five ultraviolet photodetectors. Their performance was thoroughly evaluated, demonstrating that all devices efficiently responded to 365 nm light. Notably, the photodetector with 1% Ga⁃doped ZnO microrods achieved superior performance, delivering a responsivity of 13.13 A/W, a gain of 44.63, and a specific detectivity of 3.31×10¹² Jones at 365 nm. Its response and decay times were recorded at 12.3 s and 36.4 s, respectively. These findings suggest that an optimal Ga concentration can significantly enhance the performance of ZnO⁃based ultraviolet photodetectors. This research contributes valuable insights for the development of advanced ultraviolet photodetectors and related devices utilizing ZnO:Ga materials.