Cellulosic textiles are conducive substrates for microbial growth that can cause malodour and fabric deterioration. Considering their ubiquity in daily life, textiles can also be a potential vehicle for pathogenic transmission. Antimicrobial finishing treatments can reduce microbial growth on textiles; however, prevailing antimicrobials in textile finishing such as quaternary ammonium compounds, heavy metal salts, and nanoparticles, suffer from disadvantages such as leaching after several washings, and potential toxicity to human health and environment. This calls for a safe, effective, and durable antimicrobial for textile applications for long-term usage. In this study, several organic acids including polycarboxylic acids and phenolic acids, are investigated as durable antimicrobial finishing treatment of cellulosic fabrics. These naturally occurring compounds are known for their broad-spectrum antimicrobial activity, low toxicity, and environmental safety. The functionalized cotton is bactericidal against common nosocomial pathogens such as E. coli, S. aureus, E. faecalis, and P. aeruginosa as well as fungicidal against skin-causing infection C. albicans, with its antimicrobial performance retained up to 50 washes. It can also inactivate up to >99% of MS2 and Phi6 bacteriophages, which can be surrogate for human viruses such as enteric viruses and SARS-CoV-2, respectively. The antimicrobial treatment did not cause detrimental effect on the color and strength of cotton fabrics. The dip-coating application method is also easy and scalable for industrial manufacturing for potential use in apparel, home, and medical textiles.