The biosorption properties of a newly isolated and identified cyanobacterium called Desertifilum tharense were investigated in the current study. Following morphological and molecular identification (16S rRNA sequencing analysis), the food colorant removal potential of this new isolate was determined. Moreover, the isotherm, kinetic, and thermodynamic studies were performed, and also the biosorbent characterization was studied after and before colorant biosorption with FTIR and SEM analysis. Additionally, the changes in chlorophyll content of the biosorbent were examined after and before colorant treatment. The newly isolated cyanobacterial biosorbent removed 97% of Allura red food colorant/dye at 1,500 mg L-1 initial dye concentration successfully at optimal conditions. Langmuir isotherm and pseudo-second-order kinetic models were fitted with the biosorption of the dye. The D-R model showed that the biosorption process physically occurred. The chlorophyll-a content of the biosorbent was negatively affected by the biosorption. The newly isolated and identified cyanobacterium seems to be a successful candidate for the use to treat highly dye concentrated wastewaters.