Concrete durability is a critical factor influencing the longevity, safety, and sustainability of infrastructure, particularly under aggressive environmental conditions. Conventional ordinary Portland cement (OPC) concrete is susceptible to deterioration mechanisms such as chloride-induced reinforcement corrosion, sulphate attack, carbonation, and acid degradation, which compromise structural integrity and service life. The partial replacement of OPC with supplementary cementitious materials (SCMs) has emerged as an effective strategy to enhance durability while reducing the environmental footprint of concrete. This review critically examines the performance of major SCMs, including fly ash, ground granulated blast furnace slag (GGBS), silica fume, metakaolin, rice husk ash (RHA), and limestone calcined clay cement (LC3), in aggressive environments. The review highlights how SCMs influence microstructural properties, such as pore refinement, chloride binding, and formation of secondary hydration products, thereby improving resistance to chloride ingress, sulphate attack, carbonation, and acid exposure. While SCMs generally enhance durability, certain limitations, such as increased carbonation depth in high-volume fly ash and slag systems, are discussed. Furthermore, factors influencing performance such as SCM type, replacement level, curing conditions, and exposure environment are analysed.