In this study, waterborne polyurethane dispersions (FCHB-WPUDs) were synthesized using biobased monomers, such as polyol from fenugreek oil, emulsifier from corn oil, and 1,4-butanediol (BDO) as a chain extender. The FCHB-WPUDs, prepared through the prepolymer polymerization route, were characterized using FTIR, TGA, DMA, SEM, DLS, and swelling tests. When applied to poly-cotton fabrics, they significantly enhanced various fabric properties. Notable improvements included washing fastness (from 3 ± 0.01 to 4/5 ± 0.03 for dyed and 3 ± 0.02 to 4/5 ± 0.02 for printed fabrics), rubbing fastness (from 3/4 ± 0.02 to 4/5 ± 0.02 for dry dyed and 2/3 ± 0.02 to 3/4 ± 0.03 for dry printed fabrics), and perspiration fastness (from 3/4 ± 0.01 to 4/5 ± 0.02 for acidic dyed and 3/4 ± 0.03 to 4/5 ± 0.02 for alkaline printed fabrics). Additionally, tear strength (from 9.11 ± 0.04 N to 13.75 ± 0.04 N for dyed warp and from 14.30 ± 0.03 N to 18.81 ± 0.02 N/m for printed warp) and tensile strength (from 361.17 ± 6.84 N to 493.26 ± 8.72 N for dyed warp and from 413.68 ± 6.90 N to 543.81 ± 8.58 N for printed warp) were improved. These enhancements are attributed to the increase in CODHA moles as an internal emulsifier, from 0.2 mol to 1.0 mol in the FCHB-WPUDs. The study suggests that FCHB-WPUDs could replace petrochemical-based monomers such as Dimethyl propanoic acid (DMPA) and Dimethyl butanoic acid (DMBA), offering a more economical and efficient solution for textile finishing.