Rising environmental concerns toward the use of synthetic chemicals as well as global acceptance of natural products has emphasized the need for exploring novel and sustainable sources of eco-friendly dyes for the textile sector. Our study was conducted to explore the natural colorant potential of black carrot (Daucus carota L.) plant residue for textile processing and optimizing conditions for cotton dyeing. Cotton fabric was dyed using black carrot-based dye, extracted in varying media. The results revealed that black carrot colorants produced darker shades when extracted in acidified methanol media. Excellent color strength of cotton fabrics were found at 70°C by coloring for 55 minutes using 4.0 g of salt (NaCl) as an exhausting agent. The bio mordants as well as chemical mordant were employed to improve color strength properties. In the case of chemical mordanting, 6% tannic acid and 8% iron sulphate as pre-mordant and 8% tannic acid and 2% iron sulphate as post-mordant showed maximum color strength values. Similarly, using bio mordanting, 2% of turmeric (Curcuma longa L.) and 6% of henna (Lawsonia inermis L.) extracts as pre-mordant, as well as 8% of turmeric and 4% of henna extracts as post-mordant showed maximum color strength values. Dyed cotton fabrics exhibited best color fastness properties in term of light, washing, dry and wet rubbing fastness.