Patient safety remains one of the most important dimensions of healthcare quality, with preventable adverse events continuing to contribute significantly to morbidity, mortality, prolonged hospital stays, and increased healthcare costs worldwide. Nurses constitute the largest proportion of the global healthcare workforce and maintain continuous contact with patients, positioning them as key contributors to patient safety initiatives. This systematic review aims to synthesize current evidence regarding the role of nurses in improving patient safety across diverse healthcare settings. Electronic databases including PubMed, Scopus, Web of Science, CINAHL, and Google Scholar were searched for studies published between 2015 and 2025. Eligible studies investigated nursing interventions, safety practices, and organizational factors associated with patient safety outcomes. The findings demonstrate that effective communication, medication safety, infection prevention, patient identification, fall prevention, clinical surveillance, patient education, teamwork, leadership, and technological integration significantly enhance patient safety. Furthermore, supportive organizational culture, adequate nurse staffing, continuing professional education, and implementation of evidence-based protocols substantially reduce medical errors and improve healthcare quality. Despite considerable progress, challenges such as workforce shortages, burnout, heavy workloads, and limited access to continuing education remain significant barriers. Strengthening nursing leadership, promoting a culture of safety, and investing in workforce development are essential strategies for improving patient safety globally.