The development of multifunctional textiles with enhanced ultraviolet (UV) protection has attracted increasing attention due to the growing demand for protective and high-performance clothing. In this study, cotton fabrics dyed with reactive dyes at three dye concentrations (0.5%, 1.5%, and 3.0% owf) were functionalised with titanium dioxide (TiO₂) nanoparticles using a pad-dry-cure process. The influence of TiO₂ concentration and washing on colour strength, colour fastness, UV protection, fabric stiffness, and pad–dry–cure immediate washing resistance was investigated through colorimetric measurements, FTIR spectroscopy, SEM analysis, and ultraviolet protection factor (UPF) evaluation. TiO₂ treatment produced only minor changes in colour strength, while colour fastness and fabric stiffness were largely preserved. FTIR and SEM analyses provided evidence consistent with the deposition of TiO₂-containing material and its partial removal after washing. The most significant improvement was observed in UV protection, with TiO₂-treated fabrics exhibiting substantially higher UPF values than untreated samples, while maintaining enhanced protection after laundering. These findings demonstrate that TiO₂ nanoparticle pad–dry–cure treatment is an effective post-dyeing strategy for improving the UV-protective performance of reactive-dyed cotton fabrics without compromising their colour durability or handling characteristics.