The increasing prevalence of antibiotic-resistant infections globally emphasizes the urgent need for effective antimicrobial strategies. Photocatalysts, known for their efficiency, broad-spectrum activity, and environmental benefits, present a promising alternative. With the development of natural solar light driven photocatalysts, the antimicrobial and bactericidal range has been further extended. Photocatalytic materials can be activated by various light wavelengths to generate reactive oxygen species (ROS), which can effectively eliminate a wide range of pathogenic microorganisms including bacteria, fungi, and protozoa. However, the limited optical response range, suboptimal bandgap, and slow electron cycling limit the efficient generation of ROS, resulting in lower sterilization efficiency of photocatalytic antimicrobials. Additionally, the short half-life and limited migration distance of ROS restrict their antimicrobial activity. This review focuses on the process and mechanism of ROS generation in photocatalytic reactions, and highlighting the recent advances in the typical photocatalysts. We also explore strategies to enhance ROS diffusion and utilization, including morphology control, noble metal deposition, doping, co-catalyst loading, vacancy introduction, surface functionalization, and heterojunction construction. These strategies aim to increase the efficiency of ROS generation and prolong their activity, thereby enhancing the overall antimicrobial effectiveness. Thereafter, the review presents state-of-the-art applications of photocatalysts in water purification, medical coatings, and air disinfection. Furthermore, it explores key challenges and opportunities that may drive future innovations and advancements in photocatalytic antimicrobial applications, aiming to develop more effective and sustainable solutions.