||This study represents a well dispersed gold nanoparticles (AuNPs) synthesis process via cellulose nanocrystals (CNC) as both reducing and supporting role with out using any other reducing and supporting agent. The synthesis process is ultrafast and complete within 25 seconds of time using microwave irradiation. The entire synthesis process is very fast, cost-effective, sustainable and eco-friendly. The synthesized (AuNPs/CNC) nanocomposite was investigated by using TEM, SAED, FTIR, EDX, XRD, and UV-Vis spectroscopy. The synthesized AuNPs/CNC nanocomposite exhibited excellent degradation properties against various organic dyes.