Rapid population growth and climate change have increased global water scarcity, particularly in saline coastal regions. Sustainable management approaches are therefore necessary. Brackish water desalination powered by renewable energy is one encouraging solution. The current review inspects the operational performance, cost-effectiveness, and environmental sustainability of photovoltaic (PV) solar-powered reverse osmosis (RO) systems for brackish water desalination. Considering on two decades of open literature, this review synthesizes outcomes related to system configuration, energy efficacy, economic viability, and environmental effects. PV-RO system optimisation is also investigated through experimental studies, techno-economic analyses, and simulation models. The chief performance indicators of water recovery rate, specific energy consumption (SEC), and levelized cost of water (LCOW) are appraised. The results specify a clear relationship between the considered performance indicators and system scale and geographic context. Statistically, the SEC ranges between 0.63 to 3.2 kWh/m³, and LCOW varies between $0.0022 and $5/m³. Notably, the operational reliability is improved via integration of battery storage or wind energy in hybrid systems. Also, the energy efficacy and freshwater production are improved by 14.3% and 2.7%, respectively, via utilising solar thermal preheating technique. Field installations in Bangladesh, Tunisia, and Jordan establish that PV-RO systems can meet various socio-environmental requirements, attaining water recovery rates of 70–95.33% and salt rejection beyond 98%. This review delivers vital visions for engineers, researchers and policymakers, directing to device renewable energy-driven desalination systems. Supporting these technologies can improve global water security while bring into line with environmental sustainability goals.