<p>Water scarcity is one of the most important issues presently facing the world, and the need is to develop innovative and sustainable water purification techniques. Photocatalytic–desalination systems based on a combination of photocatalysis technology for pretreatment followed by conventional desalination technologies have shown great potential. This review discusses the feasibility of the combination of photocatalytic pretreatment and desalination as a hybrid method. The review focuses on different photocatalytic materials such as titanium dioxide (TiO₂), graphitic carbon nitride (g–C₃N₄) and composite catalysts as for their performances in water treatment. Furthermore, the paper explains in detail the combination of photocatalysis and desalination technologies including reverse osmosis (RO), electrodialysis (ED) and membrane distillation (MD) and the synergistic effects which boost the desalination performance. Although photocatalytic pretreatment–desalination systems show considerable potential, important research gaps remain regarding photocatalyst stability, long-term reusability, reactor scalability, cost optimization and practical system integration. The specific contribution of this review lies in its critical synthesis of recent literature on photocatalytic pretreatment–desalination systems, with particular emphasis on emerging photocatalytic materials, contaminant transformation pathways, membrane fouling mitigation, hybrid system configurations, sustainability challenges and future scale-up requirements. By consolidating current advances and unresolved limitations, this review provides a structured reference for the development of more efficient, durable and sustainable hybrid water purification technologies.</p>