Reusing textile waste instead of disposing of it is becoming increasingly important for environmental sustainability. This study evaluates the flexural performance of concrete beams reinforced with carbon nanotubes (CNTs) and recycled polyester fibers integrated into non-biodegradable, sustainable needle-punched nonwoven geotextiles. Our investigation shows that needle-punched nonwoven geotextiles with higher mass per unit area (up to 487.8 gm/m²) and thickness exhibit significantly greater cross-direction tensile strength, achieving increases of approximately 25% due to optimized fiber orientation. Increased fabric mass and thickness enhance grab tensile strength, leading to a 20% improvement in the durability of the cross-sectional areas of the beams. The incorporation of CNTs in concrete beams reduces fracture widths by 30% and delays crack propagation, resulting in narrower cracks and increasing the load-carrying capacity by 15% compared to control beams. Concrete beams reinforced with polyester nonwoven geotextiles demonstrate ductile behavior, with a 40% increase in deflection before failure, and failure concentrated predominantly in the flexural zone. The diverse cracking patterns induced by the textile reinforcement allow these beams to absorb 50% more energy post-failure compared to control beams, showcasing an impressive capacity for deformation. Interestingly, aside from the wrapping angle, the specific properties of the polyester nonwoven geotextiles showed minimal influence on overall beam behavior. While the addition of CNTs marginally increased flexural resistance to cracking by 10%, the textile-strengthened beams exhibited superior load-carrying capacity and stiffness—up to 15% higher—compared to both control beams and those reinforced solely with CNTs. In summary, this research highlights the combined potential of carbon nanotubes and textile reinforcement to significantly enhance the performance and ductility of concrete beams. These findings provide valuable quantitative insights for sustainable structural applications