The present study aimed to evaluate the efficiency of hexavalent chromium Cr(VI) removal from synthetic waters using locally available Cyanobacteria is also called blue-green algae are commonly found in lakes, rivers, and ponds. Various sorption factors like optimum pH, period of exposure, biomass dose, and primary chromium concentrations were investigated to originate their impacts on the sorption of Cr(VI). FTIR (Fourier-transform infrared spectroscopy) and SEM (Scanning electron microscopy) were used to examine the biosorption mechanisms of Cr(VI) ions onto blue-green algal biomass. The Langmuir and Freundlich isotherm models accurately illustrate the equilibrium experimental results. The Results indicated that the biosorption of blue-green algal biomass was shown to be biomass and pH-dependent. The hexavalent chromium removal efficiency was found to be 97.6% for an initial chromium concentration of 500 mg/L within 60 minutes at pH 2, 250 rpm, and a 10g/L blue-green algal biomass dose. According to the Langmuir isotherm, the highest biosorption ability was about 396 mg/g of dry biomass, and the Freundlich constants Kf and n were 0.514 [mg/g (1/mg) n] and 32.73, respectively. At the outset, the study of “blue-green algae” can be well-advised as a propitious and precious universal adsorbent to treat the waters contaminated with toxic Cr(VI) ions.