The decolorization of reactive yellow 145 from wastewater in batch mode of operation using groundnut shell-based biochar was studied in the present research. The adsorption process was studied by investigating the effects of different adsorption variables such as temperature, initial dye concentration, pH, and biochar dosage. The results showed that biochar dosage had a substantial impact on dye absorption potential. The equilibrium biochar dosage was determined to be 1 g/L, with an absorption capacity of 7.33 mg/g. The effect of pH was examined by varying between 2.0 and 5.0, and equilibrium pH was obtained at pH 2.0. The effect of temperature was examined by varying temperature ranges from 30 to 45°C, and the optimum condition was identified as 35°C. The characteristics of biochar were studied using analytical instruments, and results concluded that dye sorption onto biochar resulted in variation of biochar. Desorption studies were carried out to evaluate the biochar potential by examining various elutants and altering the solid to liquid ratio. Groundnut shell-generated biochar was reported to remediate dye-bearing Remazol wastewater with a removal effectiveness of about 62% based on the experimental data.