India faces two growing environmental challenges: synthetic textile waste accumulating in landfills and millions of tons of cotton stalks burned after harvest. This research transforms these waste materials into high-performance wood-plastic composites (WPCs) by replacing virgin PVC and PP with recycled synthetic textiles and substituting conventional wood flour with cotton stalk flour. Experimental composites mirrored commercial formulations in composition and processing. Testing across six properties showed comparable performance to commercial products, with the PP-based composite (CSRPP) absorbing 49% less moisture than its commercial counterpart—an estimated 20–25% cost reduction while addressing critical environmental challenges. This validates a circular economy approach that diverts waste from landfills, reduces deforestation pressure, and creates sustainable building materials.