An eco-friendly single step process for free carrier dyeing and anti-UV/antibacterial functional finishing of alkali-treated PET fabric using TiO2 NPs as safe carrier and environmentally benign functional additive along with disperse and cationic dyes at mild temperature is successfully developed. The obtained data demonstrate that increasing TiO2 NPs concentration up to 8 g/L, dyeing temperature up to 100°C for 1h, and dye concentration up to 3% (owf) results in a significant improve in: color strength, anti-UV blocking ability as well as antibacterial efficacy against the tested S. aureus and E. coli pathogenic bacteria. On the other hand, the variation in color strength, fastness properties as well as in the imparted anti-UV and antibacterial functionalities is governed by type of the used dye. SEM and EDX analysis for selected cationic dyed/functional finished samples confirmed the presence of Ti-element in addition to carbon, nitrogen and oxygen onto the simultaneously dyed/functional finished fabric.