Due to the lack of UV-protective properties for cotton textiles and the potential of cotton textiles to cause microbes to their users, we synthesized benzimidazole Schiff base derivative (BZI) namely N-((1H-benzo[d]imidazol-2-yl)methyl)-1-(4-fluorophenyl)methanimine and their V(III), Fe(III), Co(II), Ni(II), and Cu(II) complexes as UV protection and antimicrobial agents for cotton textile. Several techniques investigated these compounds: 1H, 13C NMR, IR, UV-Vis, elemental analysis, DTA, and TGA. The Schiff base ligand behaved as a bidentate ligand. The prepared ligand and its complexes are used to treat the cotton fabrics (CFs) by immersing the fabric in the solution of the samples under ultrasonic. The treated cotton fabrics were investigated using IR and SEM-EDX analysis. The UPF values of the treated cotton fabric were obtained. The results showed that the cotton fabric treated with Fe(III) and Cu(II) complexes had excellent UV protection with UPF values of 50+. The disc diffusion method evaluated the treated cotton fabric's antimicrobial activity. The antifungal activities of the treated CFs demonstrated that the Co(II)-BZI-CF was active on C. albicans with an inhibition zone of 12 mm, while the other samples were inactive on C. albicans and A. flavus. The V(III)-BZI-CF and Fe(III)-BZI-CF had no activity against S. aureus and E. coli bacteria while the other samples gave an inhibition zone of between 10 to 17 mm. Unlike previous studies that primarily focused on either UV protection or antimicrobial properties of metal complexes separately, this research integrates both functionalities by synthesizing benzimidazole Schiff base metal complexes and applying them to cotton textiles, demonstrating enhanced UV protection and selective antimicrobial activity.